Accessories--like bat, tiger, cat ears, capes, monk robes, strange or hairy hands, feet, horns, tails, noses, whiskers, feathers, headpieces, hats, swords, magic tricks and masks -- work wonders in the Halloween special-effects department. Here are some leads: District

Off the Cuff. For $5 your face becomes a mammoth lip, $1 buys you a Lone Ranger half-mask, $50 a used tux, and $22 gets one of the cheapest feather boas around. Maryland

Artistic Dance Fashions, Bethesda. The bargain here is a showgirl costume for $15, but catch their imaginative line of headpieces, too.

Dream Wizards, Rockville. A fantasy shop that specializes in makeup and special effects, such as spider webbing ($4.95), flash paper and hand flashers for flame-throwers, and a new substance called Fang Form ($5 a kit), for shaping your own -- comfortable -- fangs.

Kinetic Artistry, Takoma Park. Theatrical supplies include eerie lighting and smoke effects, plus two types of fog generator (chemical and dry-ice, the latter producing a low-lying fog). Costume items include Afro wigs in 13 colors, washable hair coloring in orchid and other colors, and 12 battery-operated lights, in case you want to be a Christmas tree but don't want to hang around a wall socket all night.

Nut House, Wheaton. Simple costumes, accessories and peanuts in the shell. Virginia

Art Stone, Fairfax. Dance supplies, costumes and makeup.

Bottoms Up, Springfield. Makeup and accessories in a store that caters to professional clowns.

Stein's, Arlington. Accessories and dance supplies that stay within the family budget. Vintage Clothing

If you lean less toward the San Diego Chicken and more toward a Victorian lady, flapper, Gibson girl, zoot-suiter, or Humphrey Bogart lookalike, check out these shops, some of which are cher as well as chic:

As Time Goes By, 655 C St. SE, 543-7877.

Blue Moon, 2435 18th St. NW, 265-8113.

Broadway Baby, 1641 Wisconsin Ave. NW, 338-7355.

Classic Clothing, 3701 Benning Rd. NE, 396-2210; and 1015 Wisconsin Ave. NW, 965-2120.

Great Gatsby, 218 N. Lee St. (second floor), in Old Town Alexandria, 683-0094.

Jameson & Hawkins, 3061 1/2 M St. NW, 965-6911.

Unforgettables, 1083 Thomas Jefferson St. NW, 965-5644.

And don't forget the thrift stores, a marvelous if musty source of cheap old clothing like men's jackets for hobos, baggy pants for clowns, flared skirts and bobby socks for the '50s look, aprons for Raggedy Anns, old shoes for clown feet, long black lace-up shoes for witches, old linens for dyeing and making into capes and other costumes.

Look under "Clothing, Bought and Sold" in the Yellow Pages, as well as "Thrift Shops."