Every July, my Christmas plan is hatched: great gifts, even for the hard-to-buy-for; shopping to start in September, be done by November, everything wrapped, tagged and ready.

The plan is a perfect one, and it works every year -- not for happened again, leaving me no time to enjoy the season.

Never mind, there are lots of fun things to do, and here's the cream of them. If any are crowded, don't blame me -- I'm still in the midst of my October shopping.

IN THE HEART OF TOWN: Past White House dwellers weren't so lucky and couldn't put off sending presidential cards at the last minute. They had to have their cards signed, sealed and delivered in a fashionable time that lent them some respectability.

OFFICIAL PRESIDENTIAL CHRISTMAS CARDS, through last year's card sent by Ronald and Nancy Reagan, are on display through January 4 on the second floor of Smithsonian's Museum of American History. No Christmas card should be without a seal, and this exhibit is no exception.

FIGHTING THE WHITE PLAGUE: 75 YEARS OF CHRISTMAS SEALS, also on the second floor, offers 35 photos and documents related to the National Lung Association's 75-year battle against TB and other lung diseases. Downstairs in the pendulum area on the first floor can be found an antique toy collection, sleds and hobby horses clustered around THE TREES OF CHRISTMAS, 12 living trees from four to 12 feet tall, decorated in a dozen themes. One, Companions of Childhood, displays children's ornaments of felt, inspired by classical literature, history, modern comics and television.

POINSETTIAS: Who knows what they did for Christmas flowers before Joe R. Poinsett returned home? Poinsett, the U.S. minister to Mexico, introduced the Euphorbia pulcherrima to this country in 1830. Better known as the poinsettia, more than 3,000 of these blooming red, white and pink flowers, representing the newest and best varieties, can be seen at no cost at the ANNUAL POINSETTIA SHOW continuing at the Botanic Gardenthrough New Year's Day. Call 225-6670.

ANIMALS ENJOY CHRISTMAS, TOO: HELP THE BIRDS MAKE IT THROUGH THE WINTER or, better yet, give the underbird a break. Learn what feed to use and how to attract them, Saturday at 11 at the Kenilworth Aquatic Gardens. Call 426-6905.

The next day you can help decorate a tree with your own popcorn, cranberries and seed balls for the wildlife of the park at Great Falls Park, Virginia. Call 759-2915.

MESSIAHS: If you've got the musical spirit, the PAUL HILL CHORALE wants you in the Kennedy Center Concert Hall on Saturday at 8:30, Sunday at 7 or Monday at 8:30 for the Messiah SingTickets range from $4 to $16.50 and can be ordered at 857-0900. A sold-out Thursday performance at 8:30 will offer only no-show seats at the door.

Give the Prince George's Choral Society and Eleanor Roosevelt Senior High Orchestra a helping voice as St. Joseph's Church on Capiol Hill (Second and C streets NE) presents a MESSIAH SINGALONG, Sunday at 7. Contact 547- 1223 for details.

The Alexandria Choral Society presents its "Messiah" Saturday at 8:30 and Sunday at 3 at Christ Church, 118 North Washington Street in Alexandria. Over in Fairfax, a "Messiah" singalong happens on Sunday at 4 at Fairfax High School Auditorium, 3500 Old Lee Highway. For details call 379-4481.

KENNEDY CENTER HOLIDAY FREEBIES: TOM GAUGER and WMAL radio will do a live five-hour broadcast from the Kennedy Center Concert Hall beginning at 10 on Christmas Eve. Guests include the Chantilly Secondary School Symphonic Wind Ensemble and Jazzin' Stage Band, the Montgomery County Youth Orchestra and County Chorus, the orchestra and chorus of D.C. Space, Dorothy Kingston and David Troupe along with WMAL personality Karen Henderson. The Salvation Army will be honored while members of the Reston Chorale and the Choral Arts Society perform in the grand finale. Meanwhile, in the Grand Foyer, the Nubian League will combi cultural information, music and dance in a program called "Kwanzaa Means First Fruits." Also scheduled in the foyer are the Mountain Laurel Band, McLean Jazz Workshop and the Chinese Spring Thunder Dance Group in DANCE OF THE FLYING ANGELS from 2:30 to 3:15. All are free and require no tickets. The audience may come and go freely throughout the broadcast.

MORE JOYFUL NOISES: The 50-voice-strong mixed choir from St. John the Baptist sings seasonal music on Friday from 7:15 to 8 in the Kennedy Center's foyer; the next day a variety of holiday events there run from 1 to 3 and 7 to 8:15. On Sunday at 1 the New Age Woodwind Quintet will do new arrangement of French Christmas carols followed by chamber music by the American University string quartet at 2. An organ recital and demonstration can be heard in the Concert Hall on Wednesday at 1. See the Alexandria Community Singers directed by Amelia McCuen as the choral group sings uptempo Christmas music, Thursday at 6:15 in the grand foyer. At 7:15 they'll by edged out by Baroque, Renaissqnce and special seasonal music for the instruments of the Monumental Brass Quintet. Free musical events at the Kennedy Center continue daily through the year's end. Call the Concert Hall for additional listings at 254-3776.

The Model Secondary School for the Deaf Sign Chorus and the Duke Ellington School for the Performing Arts Chorus perform in a WINTER CHORAL CONCERT, Friday and Saturday at 8 at Gallaudet College, Eighth and Florida NE. Adults pay $8, students $2. Call 651-5801 for voice and TDD.

HOME FOR CHRISTMAS, a musical at Forest Memorial United Methodist Church, can be seen Friday, Saturday and Sunday at 8 at 3111 Forestville Road in Forestville. Call 736- 4115, and the sixth annual RENAISSANCE CHRISTMAS will be loud and clear this weekend at the National Shrine. The National Shrine Choir, Brass Ensemble and organs, perform the music of Gabrieli, Palestrina, Schutz and Praetorius. Prices are $5.50 to $10 for shows on Saturday at 8:30 and Sunday at 3, at Fourth and Michigan NE -- or take the Metro to Brookland Station. Call 526-8300.

The NAVY BAND celebrates with two holiday concerts at Constitution Hall: "Home for the Holidays" features the Concert Band and Sea Chanters in a program of traditional holiday tune. The shows, Saturday at 8 and Sunday at 3, are free. The McLEAN CHAMBER ORCHESTRA presents its holiday pops concert Sunday at 2:30 and 5 in Alden Theater. The "Christmas Cantata," "A Christmas Festival," "Sleigh Ride" and "Bugler's Holiday" are scheduled.

ENGLISH HANDBELLS and choir music will ring out at the 9:30 and 11 o'clock Sunday services at the Wesley United Methodist Church, 711 Spring Street SE, Vienna.

The WOLF TRAP CHAMBER SINGERS give their Christmas concert Sunday at 2 at The Barns. After intermission the audience can join in with traditional carols. Call 938-2404.

Take a drive to Sully Plantation Sunday and you'll hear the MERRIE RECORDERS CONSORT in action at 2 and 3, doing Christmas and traditional melodies in Renaissance dress. Cost is $2. Call 437-1794.

The HARMONIZERS HOLIDAY CONCERT is Sunday at 2 at the Lee Center, 1108 Jefferson Street in Alexandria. It's free and for all ages. Call 838-4343.

The ST. COLUMBA HANDBELL RINGERS perform an assortment of festive holiday melodies, Sunday at 3 at the Museum of American Art, Eighth and G NW. Masur Auditorium at National Institutes of Health will have the MONTGOMERY YOUTH ORCHESTRA in its free Christmas program of Pachebel's Canon, March of the Nutcracker and March of the Toys on Sunday at 3 in Bethesda.

The TAKOMA PARK COMMUNITY Theater at Baltimore Road and Edmonston Drive. It's free.

AN ENGLISH CHRISTMAS of traditional and contemporary English music featuring the Gloria can be heard on Sunday at 7 at Bethesda United Methodist Church, 8300 Old Georgetown Road. "Jesu Bambino," "Ding Dong Merrily on High," "Sanctus" and "'Twas the Night Before Christmas" will be sung by the MOUNT VERNON SINGERS Sunday at 7 at the Old Presbyterian Meeting House on Fairfax Street in Old Town. Call 765-4808.

The CATHEDRAL OF ST. THOMAS MORE presents a traditional service of lessons and carols led by Haig Mardirosian, organist and choirmaster, on Sunday at 7:30 at Cathedral Lane in Arlington.

The NATIONAL GEOGRAPHIC SOCIETY CHORUS presents its annual Christmas program Monday in Explorers Hall, 17th and M NW. It's free at 3. Philomela, a women's consort, presents MAKE WE JOY, a festival of seasonal song and verse, Monday at 8 at the Unitarian Universalist Church of Silver Spring.

THE CHORAL ARTS SOCIETY with Norman Scribner presents its annual Christmas music at the Kennedy Center Concert Hall on Tuesday at 7:30 and Wednesday at 8. The Sunday show is sold out. Call 857-0900. A series of MINI-CONCERTS Christmas Eve begins at 7:30 at Sligo Seventh-Day Adventist Church on Flower and Carroll avenues in Takoma Park. The first concert will be followed by five others at 20-minute intervals. Call 270-6777.

Flory Jagoda's SONGS FROM YUGOSLAVIA will be presented in the pendulum area of the Museum of American History at noon the day after Christmas.

ZEMER CHAI follows the next hour with a Jewish choral music program, and the Aqua String Band, Philadelphia New Year Shooters and Mummers Association performs stringband music until 3. The Rochelle Helzner Quartet winds up the four-hour program with Jewish folk music. You'll hear MIDNIGHT SPECIAL, a Sweet Adelines quartet; SINGERS MADRIGALE and barbershop music from OL' LINE FOUR as they rove all four floors.

Don't miss THE OVER THE HILL GANG at 2 in the Hall of Musical Instruments in an hour- long family concert featuring homemade instruments. The holiday celebration at the Smithsonian continues throughout the week with Christmas, Hannukah and New Year's activities from George Washington's time to present. It happens noon to 4 daily, and the Mummer's Parade runs from 1:30 to 3. It's all free.

SEASONAL SPECTACLES: Dance into the Christmas spirit when the Arlington Ballet presents CELEBRATION EN POINTE Friday and Saturday at 7:30 at the Thomas Jefferson Community Theater at 125 South Old Glebe Road, Arlington. Call 979-4865.

Or step back a bit through the space and find the STAR OF BETHLEHEM as it was 2,000 years ago on Friday and Saturday at 7:30 and Sunday at 3 and 4:30 at the Arlington Planetarium at 1426 North Quincy Street. Cost is a dollar, but call ahead and reserve. Now you can cruise through Christmas at Grace Baptist Church at 7210 Race Track Road where a DRIVE-THRU NATIVITY SCENE can be seen on gasoline this Saturday from 6 to 9. Church members will portray Mary, Joseph, the innkeeper, the wise men, shepherds, angels and townspeople. The joyous ride is free.

SIR GAWAIN and the GREEN KNIGHT will be performed by the St. Mark's Dance Company Saturday and Sunday at 3 at 301 A Street SE. Tickets for this comedy are $3 for adults and $1.50 for kids. Call 547-1936. Celebrate Sunday at 6:30 or at 8 at the Round House Theater's HOLIDAY PAGEANT with a joyful and sometimes crazy set of improvisational skits by the house acting company, the Children's Chorus, carol-singing and St. Nick for only $1. The Round House is at 12210 Bushey Drive, Silver Spring. Call 468-4234.

It's time again to get in the inside word from a Hill aide. The walls may have ears, but THE CAPITOL STEP make wise cracks, music, and as a bipartisan political satire group made up of staffers, step on toes in both parties. The second annual Christmas show is free to all and happens Wednesday, December 22, at 7:30 in Room 2261 of the Rayburn House Office Building. Shepherds, kings and a baby make a scene with carolers at the annual CHRISTMAS EVE PAGEANT on December 24 at 4, at Washington Cathedral. A carillon recital at 9:15 and an organ prelude at 9:40 are follow by a Christmas Eve service at 10.

Enjoy a RENAISSANCE CHRISTMAS with the Society for Creative Anachronism on December 30. Beginning at 7, the celebration features 15th-century music, dance and costumes at the Silver Spring Library, 8901 Colesville Road, Bethesda. Call 565-7689.

The OBADE BII DANCERS, DRUMMERS AND SINGERS of Ghana will give a free concert of music and dance on December 30 in Baird Auditorium, Museum of Natural History. Call 287- 3490.

A CHILD'S CHRISTMAS: New house starts are on the rise when it comes to GINGERBREAD HOUSES and kids 8 to 12 years old. For $12 on Saturday from 10:30 to 12:30 children can learn how to bake holiday cookies at L'Academie de Cuisine, 5021 Wilson Lane in Bethesda. Call 986-9490.

You can see SANTA ON ICE at the Mount Vernon Sports Complex from 6:30 to 10. Music and holiday festivities are included in the admission of $3.75 for adults and $3 for children. Call 768-3223.

Santa can also be seen with Mrs. Claus and the elves at the Christmas SKATING PARTY at the Prince George's Plaza Community Center the same evening from 7 to 10. Bring your own roller skates or rent them. He'll take gift requests and Mrs. Claus will decorate cookies and wrap elf gifts. It's at 6600 Adelphia Road, Hyattsville, and the cost is $1. (Call 864-1611.)

"Brunch with Santa" begins at 9 Saturday morning with the Blue Sky Puppet Theater's performance of A CHRISTMAS GIFT at Tucker Road Community Center, Fort Washington. To make reservations call 248-4404.

The RECYCLEWORKS in Falls Church will show children from five to seven how to make snowflakes, garlands and cones for the family tree from 10:30 to 11:45 on Saturday. Then, from 12:30 to 1:45, kids eight to 12 can learn to make gifts for their parents at 132 North Washington Street. Both classes are $5, and required reservations can be made by calling 241-0444.

ANGELS, a musical for young people performed by children's choirs, is free on Friday and Saturday at 7:30 at Fairfax Presbyterian Church, 10723 Main Street, Fairfax City. Call 430-2964. The Museum of American Art presents a PUPPET SHOW with a visit to Santa's workshop, Sunday from 12:30 to 1:30; it's free at Eighth and G NW.

While you're visiting the NATIONAL ZOO this Sunday, you can hear live dramatic readings of holiday tales presented at no cost by Children's Radio Theater from 1 to 3:30.

HOLIDAY MUSIC from Southeast Asia, Germany and England for children's groups can be heard at 2 on Saturday afternoon at Renwick Gallery, 17th and Pennsylvania NW. By the day after Christmas, cabin fever could be enjoying another epidemic. If it happens in your home, let the National Museum of American History prescribe DOUG LIPMAN; he can be caught telling stories every other half-hour beginning at 12:30 in the First Ladies Hall, while Colonial puppeteer DAVID BALLARD keeps the same schedule in the third-floor special exhibits area with the Punch and Judy Show beginning at 1. The pair will be there December 26 through 30.

Kids can learn all about the African harvest celebration, KWANZAA, at a workshop where artist Winston James instructs children six to 12 in making a Kwanzaa banner. Classes are offered at 2 daily, December 27 through 31; call 287-3490 to reserve.

GLITTERY GETAWAYS: A trip to the CATOCTIN MOUNTAIN ZOO may be in order after all the last-minute shopping madness, and you can repair your nerves in the land of clean a area where petting and feeding animals, including deer, is encouraged. The zoo will remain open through January 3 and admission is $2. The zoo is roughly 15 miles North of Frederick, on U.S. 15. Call 301/6663-8703.

While you're there, you might want to take in the FESTIVAL OF LIGHTS in Frederick: The whole town comes out with candles and carols in the spirit of old-time fun and tradition. Many of the town's history-laden churches will open their doors for touring before 7:30, when the festival begins. For more information call 301/663-8703.

NEWER AND NEARER: Take a large step into the past and tour the WOODROW WILSON HOUSE and a still larger step back at the DECATUR HOUSE by taking advantage of the $2 holiday special for both houses, trimmed for the occasion and looking just as they did when Commodore Stephen Decatur and his wife, Susan, lived in theirs in 1819 and when the Wilsons were in retirement in the early 1920s. A special Sunday gathering at the Decatur House from noon to 4 sports all the lavish Christmas trimmings, traditional mulled cider and gingersnaps, along with two half- hours of holiday music performed by the lute duo of Linn Barnes and Allison Hampton. For more information and prices, call 673-4210 or 673-4273.

The ARLINGTON HOUSEz a.k.a. Custis-Lee Mansion, will look just as it did before the Civil War through January 2. Hours are 9:30 to 4:30 (closed Christmas and New Year's Day), and the house is steeped in local history and offers a striking view of the Federal City's skyline. Call 557-0613.

And don't forget THE WHITE HOUSE while you're at it. The annual candlelight tours of the president's home run December 28 to 30, 6 to 8 p.m., and visitors should go directly to the East Gate. Call 472-3669 for additional information.

LONG AGO AND FAR AWAY: Relive the colonial years with a stop at the home of one of Maryland's four signers of the Declaration of Independence. Citrus fruits, grapes, apples, cranberries and pears, typical of colonial fruits as well as cakes, jellies and sweetmeats will be on display at WILLIAM PACA'S MANSION, at 186 Prince George Street in Annapolis. Hours are Tuesday through Saturday, 10 to 4, and the following two Sundays from noon to 4. The house will be closed Mondays and Christmas Day. For further information, call 301/267-8149.

A MERRIE OLDE CHRISTMAS, performed by the Renaissance Ensemble of Baltimore, includes yule songs and carols designed to bring warm holiday feelings. At Park School on Old Court Road, Brooklandville, on Saturday at 8 and at Lovely Lane, 2200 St. Paul Street, on Sunday at 3. Call 301/889-3712 for ticket information.

FEASTS FROM ALL OVER: The seven principles of KWANZAA, the African harvest tradition, its ceremonies, festivals and family gatherings, will be explained in a craft workshop, December 30 from noon to 3. Music, storytelling and games are part of it in the third-floor auditorium of the Museum of African Art, 318 A Street NW. Call 287-3490.

HAPPY YEAR'S END: Alexandria, Virginia's Little Scotland, celebrates HOGMANAY or Old Year's Night on the 31st at the home of one of Alexandria's first leading residents, John Carlyle. A slection of meat pies, bridies, shortbread and other refreshments will be served with the sounds of the Alexandria Pipes and Drums, the official local bagpipe band. The party begins at 10 at 121 North Fairfax Street. Tickets are $20 each or $30 per couple and must be paid for by December 27. Call 549-0205.

ARTFUL HOLIDAYS: The ART BARN offers a holiday special of batik, basketry, fiber sculpture, weaving, porcelain, pottery, prints and jewelry last-minute gift-seekers with "Art For Gift's Sake," which includes fiber art, ceramic sculptures, paintings and an "original print calendar," through December 22 at 1821 Q Street NW. Call 332-2121.