Prime cuts -- that's what is on order this fall. Designers have begun to mend their extravagant ways, curb the recent costumery and concentrate on straightforward clothes. Big puffed-out sleeves have been deflated, football-player shoulders have been tamed, overscaled silhouettes and unbounded layers have been pared away. Baggies and knickers have been trimmed back to tailored silhouettes. Tricky shapes and an overdose of details have been sidetracked as designers concentrate on more serious and more simple designs. The economy has finally returned some reality to the clothing business. Clothes are much too expensive to be frivolous. (Why would the art of wardrobe consulting be growing so fast if men and women didn't want to take clothes seriously?) Jobs are too hard to keep to be undermined by fanciful, distracting garb. The woman who can afford good fashion wants clothes that support her determination in her job, rather than distract from her efforts. The young woman lawyer, for example, is a prime customer for expensive designer clothes. She knows she won't be taken seriously in a colorful costume or in a mini-skirt. But at the same time, the young girl who would love to wear extreme, head-turning clothes can't afford them at designer prices, at least not until the third markdown.

Skipping the gimmicks and wearing simple, straightforward clothes is a lesson men learned long ago. And the calm classic style of the current crop of menswear continues this good sense. Shapes stay normal; the variation comes with the fabric and colors and the way they are mixed. Flamboyance and flash figure in socks, ties and even sweaters. But in the more basic and more expensive elements of men's clothing, the color is careful and often can be caught only with a close look at the fabric.

Just because women's clothes have gotten more serious it doesn't follow that they have to be dull. To be sensible can also be sexy. In fact the clothes, in their simpler ways, provide a background for the wearer, rather than dominating the way she appears.

Regrettably, it does not follow that because clothes are simpler, they are cheaper. Few things are so sure in this world as the rising cost of everything, including clothes. The increased cost of natural fibers on the world market and of doing business in stores, plus labor minimum-wage increases, are obvious reasons. But another cost factor is that clean-cut clothes such as these require high-quality workmanship. Poorly made clothes can be disguised by tricky design or gussied-up styling, but prime cuts depend on superior fabric and excellent construction.

The current buzzword in fashion is "architecture," referring to the clean, sharp lines in much of the clothing. Clothes are more practical, too. The wool suit is appropriate for evening with a beautiful blouse and for the office with a tailored blouse or sweater. Coats have a double purpose, as layers can be added to them for rain or cold.

Colors are familiar but refreshed. If you think there is nothing new about gray or navy blue, wait till you catch how it has been enlivened with modern cuts. If black sounds boring, imagine it as a background for bright color splashes or bold accents from patterns or accessories.

The near-classic look of the clothes provides a simple frame for the marvelous accessories of the season. Big bold jewelry can change the total look of a suit or a dress. A big coat collar or an oversized cowl neckline becomes a changeable field for a carved or sculpted stone pin.

The man-tailored hat balances the clean shape of women's clothes (shapes that were stolen from men's wear in the first place). Women started wearing hats again last summer, and now they don't want to stop. But these aren't silly hats that perch on the top of the head. And, unlike the last big hat-wearing period in the 1950s when millinery salesladies insisted on the precise way to wear each hat, this season these hats can be punched and pulled into lots of different shapes. (Don't let anyone tell you there is any one way to wear a hat.)

Shoes, too, pare down. The old pump is freshened with bold colors, sometimes more than one. The high heel is back for those who want to wear it with the shorter narrow skirts. But for those who hold out for comfort, there are plenty of mid-high heels. And to solve all the problems of what to wear with the longer skirts, designers have sanctioned the boot once more.

Colored hose remain the cheapest, easiest way to change the way a costume looks. The unexpected show of red or turquoise or gray hose is an instant pickup for favorite clothes that have hung around your closet for years and a way to brighten up the new clothes as well. And they cost less than the price of a movie ticket.

How to dress this fall? Find the best of the clothes -- simple, versatile and becoming. That's not a small task, but it's still possible at any price. That's why you should order prime cuts. CAPTION: Cover Photo, THIS FALL'S FASHION IS SIMPLICITY ITSELF, by Michael Doster; Picture 1, no caption; Picture 2, There is nothing old-fashioned about gray this season, especially in the cut of suits. The gray flannel double-breasted suit with checked shirt by Alan Flusser at The Designers; Her Low-slung glen plaid suit and cashmere sweater by Gloria Sachs at Neiman-Marcus and to order from Lord & Taylor; Stephen Allendorf earrings at Jackie Chalkley and Artwear (New York); patent pumps by Maud Frizon at Bloomingdale's and Neiman-Marcus; pantyhose by Round the Clock at Hecht's. His pin-stripe suit, shirt and silk tie by Jeffrey Banks at Neiman-Marcus; suit only at Saks Fifth Avenue. The one-button coat dress in gray wool flannel by Ralph Lauren at Bloomingdale's and Ralph Lauren-Polo ShoP; Jyunko Sonohara cuff at Artwear (New York); Judith Frey earrings from Artwear (New York); Picture 3, The gray leather blazer is teamed with tunic and narrow wrap skirt, all by Donna Karan and Louis Dell'Olio for Anne Klein & C classic trouser by Blassport at Bloomingdale's; James I. Murphy Ltd. earrings, to order from Bloomingdale's; Yves Saint Laurent suede gloves at Rive Gauche; Joan & David leather pumps at Ann Taylor; pantyhose by Round the Clock at Garfinckel's. Her black alpaca coat, cashmere argyle sweater and flannel pants by Gloria Sachs at Lord & Taylor; James I. Murphy Ltd. earrings, to order from Bloomingdale's; suede pumps by Allure at Woodward & Lothrop; Berkshire's ribbed pantyhose at Les Gals; La Crasia white long gloves at Bloomingdale's. His black alpaca steamer coat by Perry Ellis at Bloomingdale's; Alexander Julian cashmere sweater with contrast cable at Neiman-Marcus; Calvin Klein black corduroy pants at Raleigh's; tassel loafer at Brooks Brothers; Pictures 4 and 5, The double collar builds on the clean shape of a tobacco wool coat, worn over a black wool sweater dress with oversized turtleneck that can be worn as a hood, by Mrs. H. Winter at I Magnin; Robert Lee Morris copper earrings and ribbed copper cuffs at the Fendrick Gallery, Artwear (New York) and to order from Saks Fifth Avenue; Yves Saint Laurent black leather gloves with antelope trim at Rive Gauche; black opaque panty hose at Hecht's. His brown wool tweed suit, made less business without a tie, by Bill Blass, collection at Woodward & Lothrop; Perry Ellis black cableknit sweater at Bloomingdale's and The Designers.; Pictures 6 and 7, The modern topper has an angular collar anchoreed with a wooden button in ombre stripe wool and paired with cropped cuffed pant, all by Miya & Co. at Saks Fifth Avenue; polished wood earrings by James I. Murphy Ltd., to order at Bloomingdale's. Both men in Giorgio Armani tweed suits and shirts to order from Neiman-Marcus; Florsheim wing tips at Hahn's ; Alan Flusser socks at The Designers.; Pictures 8 and 9, White wool steamer coat with cap-sleeve top and classic trouser by Blassport at Bloomingdale's; James I. Murphy Ltd. earrings, to order from Bloomingdale's; Yves Saint Laurent suede gloves at Rive Gauche; Joan & David leather pumps at Ann Taylor; panty hose by Round the Clock at Garfinckel's. Her black alpaca coat, cashmere argyle sweater and flannel plants by Gloria Sachs at Lord & Taylor; James I. Murphy Ltd. earrings, to order from Bloomingdale's; suede pumps by Allure at Woodwards & Lothrop; Berkshire's ribbed panty hose at Les Gals; La Crasia white long gloves at Bloomingdale's. His black alpaca steamer coat by Perry Ellis at Bloomingdale's; Alexander Julian cashmere sweater with contrast cable at Neiman-Marcus; Calvin Klein black corduroy pants at Raleigh's; tassel loafers at Brooks Brothers.; Picture 10, Tweed jacket and wool tie by Alexander Julian at Neiman-Marcus; work shirt from Basco by Gene Pressman and Lance Karesh at Bloomingdale's. Her blazer and pullover by Perry Ellis at Saks. Jandel, Woodward & Lothrop and Saks Fifth Avenue; earrings by Cathy and Marsha for Catherine Stein at Woodward & Lothrop, I. Magin, Saks Fifth Anenue, Bloomingdale's.Picture 11, Leather and wool are mixed in her three-quarter coat by John Anthony, paired with leather skirt and a silk sweater underneath, all at Elizabeth Arden; Barbara Bolan's green suede and leather clutch at Garfinckel's; Yves Saint Laurent suede gloves with leather trim at Rive Gauche; Jyunko Sonohara earrings at Artwear (New York). His wool jacket by Perry Ellis at Bloomingdale's; leather pants by Marc Buchanan at Georgetown Leather Design.Picture 12, Her seamed coat in lead-gray wool melton with side-button closure by Lloyd Allen at Saks-Jandel, and at Garfinckel's in navy or camel, worn over Zoran black cashmere sweater at Saks Fifth Avenue; Yeohlee's spiral seamed pants at Garfinckel's; Jyunko Sonohara earrings from Artwear (New York); La Crasia red leather gloves at Saks Fifth Avenue; Andrew Geller's wedge shoes at Woodward & Lothrop and Rich's; gray panty hose by B-Line at Bloomingdal's.; Picture 13, Overshirt in wool block-plaid tops black pants with tuxedo stripe by Narcissa at Saks Fifth Avenue; cuff by Susan Tmulevich at Cachet Four Seasons; Andrew Geller wedge shoes available at Rich's and Woodward & Loghrop; hot curry pantyhose by Givenchy at Hecht's.; Picture 14, An easy shift to comfort in a dress for the office or dinner (or both) is by Perry Ellis at Garfinckel's and Saks Fifth Avenue; Patricia Underwood purple hat from Cachet Four Seasons; Kristin Moore orange drop earrings at Artwear (New York); olive pantyhose at Bloomingdale's green leather pumps by Charles Jourdan at Garfinckel's.; Picture 15, The black snap-front coat is worn over a red fleece top and skirt, but works alone as a coat dress; over it, a red sweat-shirt poncho, all by OMO Norma Kamali at Hecht's; La Crasia gloves at Bloomingdale's; His sweater by Basco at Silhouette.; Picture 16, Pants return to their proper proportion to team up with a clean-cut Jacket. Khaki wool gabardine pantsuit by tahari at Hecht's; Patricia Underwood off-sailor hat at Cachet Four Seasons; metal cuff by Ted Muehling at Artwear (New York); earrings by Kristin Moore from Artwear (New York); choker by Robert Lee Morris at The Fendrick Gallery, Artwear (New York) and to order from Saks Fifth Avenue.; Picture 17, Carolyn Doyle puts a vest over a coat for extra warmth and reverses it from black wool to khaki poplin for rainy days or just for the look of it, to order from Bloomingdale's; colors in Optics sunglasses at Bloomingdale's; James I. Murphy Ltd. dome-shaped earrings, to order from Bloomingdale's; La Crasia khaki wool jersey gloves at Bloomingdale's.; Picture 18, The pattern for sweaters is set by the texture as well as the color. Gene Pressman and Lance Karesh for Basco stripe only the sleeves on this nubby-knit, raglan-sleeve pullover, worn with Basco's gray cotton poplin pants padded for warmth, all at Silhouette; Sal Cesarani cable-knit crewneck sweater, at Garfinckel's.; Picture 19, Bold blocks of black and white build a modern wool chemise with colman sleeves by Yeohlee at Garfinckel's; ebony and ivory mixed in wood for both earrings and cuff, by James I. Murphy Ltd., to order at Bloomingdale's; black pin-stripe sheers by Berkshire at Les Gals.; Picture 20, Narcissa's teal wool jersey dress with dolman sleeves at Saks Fifth Avenue; Ted Muehling ridged cuffs and cluster earrings at Artwear (New York) and to order from The Fendrick Gallery and Saks Fifth Avenue; teal panty hose at Bloomingdale's; Vittorio Ricci T-strap pumps at Saks Fifth Avenue (beaded cummerbund not available locally).; Picture 21, The shapes may be familiar, but the texture mixes are quite special. Her angora checkerboard sweater combines with a plaid sild skirt by Gloria Sachs at Neiman-Marcus; Ted Muehling's cluster earrings at Artwear (New York); Aris black leather shortie gloves at Garfinckel's; Stuart Weitzman black silk pumps at Saks Fifth Avenue; Berkshire black sheer stockings at Les Gals. His wool plaid sweater and shirt are put over black corduroy pants by Perry Ellis at Bloomingdale's with Alan Flusser black tassel loafers at Garfinckel's.; Picture 22, Suede cape-collared blouse and smocked yoke skirt by Calvin Klein at Garfinckel's and Bloomingdale's; earrings by Kristin Moore at Artwear (New York); suede pumps by Vittorio Ricci at Bloomingdale's and Saks Fifth Avenue; panty hose from Givenchy at Garfinckel's; Yves Saint Laurent's leather gloves at Rive Gauche.; Picture 23, Smock tunic and narrow skirt, center, by John Anthony at Elizabeth Arden; Vittorio Ricci pump at Bloomingdale's and Saks Fifth Avenue; earrings by Stephen Allendorf at Jackie Chalkley and Artwear (New York); teal panty hose from Round the Clock at Woodward & Lothrop. Right, currant suede blouse and pleated pants with detachable ruffle by Sienna Leathers at Georgetown Leather Design; Jyunko Sonohara earrings from Artwear (New York). His wool sweater by Perry Ellis at The Designers; Low boots by Vittorio Ricci at Silhouette; sport watch by Heuer, to order at Charles Ernest Jewelers.; Picture 24, Velvet dresses pair up with classic black tie. Left, Calvin Klein's gray velvet dress with cinched waist at Garfinckel's and Bloomingdale's; black rodoid evening bag with tassel by Barbara Bolan available in November at Garfinckel's; Susan Tamulevich's black onyx, pearl and abalone drop earrings from Cachet Four Seasons; black patent open-toe pumps by Daisy from Garfinckel's; gray panty hose by Magninique at I. Magnin. Center, man's classic tux by Giorgio Armani available at Neiman-Marcus in October; classic evening pumps at Brooks Brothers. Black velvet drop-waist dress by Mrs. H. Winter at I. Magnin; Judith Leiber's black satin evening bag at Saks Fifth Avenue and Neiman-Marcus; black patent low-heeled pump with red rosette by Andrew Geller at Woodward & Lothrop and I. Magnin; Aris black leather gloves at Woodward & Lothrop; black sheer stockings at Lord & Taylor.; Picture 25, Even for evening the classics are refreshed by fabric and texture. The sharp lines of her cashmere mini-shift are brightened by studs of red rhinestones, by Donna Karan and Louis Dell'Olio for Anne Klein & Co. at Saks Fifth Avenue and to order from Bloomingdale's; clear, faceted earrings by Cathy and Marsha for Catherine Stein at I. Magnin and Woodward & Lothrop. For the man for evening, Pinky & Dianne for Private Label add a new twist to the "smoking" with suede tuxedo jacket and black silk shirt, along with traditional pants and cummerbund, all from The Designers.; Picture 26, There's nothing old-fashioned about these lace looks. Left, Pinky & Dianne for Private Label combine lace with red rose tulle and hand-beaded detail, worn over a camisole and with black velvet ankle-length pants at Marie Claire; red velvet slippers by Mootsie's Tootsies at Bloomingdale's and Woodies; Kenneth Jay Lane gold cuffs with inset stones at Woodward & Lothrop; faceted earrings by Cathy and Marsha for Catherine Stein at I. Magnin; black sheer panty hose by Round the Clock at Hecht's. Center, his black silk shirt and tuxedo pants also from Pinky & Dianne for Private Label at The Designers. Oscar de La Renta uses black and gold lace for a longer-than-usual tunic over black satin pants at Woodward & Lothrop; Ted Muehling's hip-riding gold belt at Artwear (New York); Berkshire's black sheer panty hose at Les Gals; black grosgrain pumps by Stuart Weitzman at Saks Fifth Avenue.; Picture 27, Natural white mink coat from the Connoisseur Collection of Baron & Hennessy at Rosendorf/Evans, Worn over white flannel pants from Blassport at Bloomingdale's; Joan David gray leather pumps at Ann Taylor; earrings by Robert Lee Morris at Artwear (New York), The Fendrick Gallery and to order from Saks Fifth Avenue. His black alpaca steamer coat by Perry Ellis at Bloomingdale's. Her black dyed ermine cape from The Tepper Collection at Sake-Jandel worn over Zoran's black gabardine pants at Saks Fifth Avenue; Kenneth Jay Lane's earrings at I. Magnin; Vittorio Ricci pump at Bloomingdale's and Saks Fifth Avenue; La Crasia gloves at Bloomingdale's. On him, white tie by Bill Blass from After Six collection at Woodward & Lothrop, black evening pumps at Brooks Brothers.; Picture 28, Geoffrey Beene's three-piece evening pantsuit, to order at Rizik Brothers and Neiman-Marcus; earrings by Cathy and Marsha for Catherine Stein at I. Magnin; Kenneth Jay Lane's necklace at Woodward & Lothrop; silk pump by Stuart Weitzman at Saks Fifth Avenue. He wears Bill Blass's white tie for After Six collection at Woodward & Lothrop.; Picture 29, Diamond-weave coat by Miya & Co. at Saks Fifth Avenue; Patricia Underwood bowler hat at Bloomingdale's; Joan & David pumps at Ann Taylor. Menswear by Giorgio Armani.; Picture 30, The wool suit for evening has dots -- with dash -- teamed, with black lace blouse, all by Mrs. H. Winter at I. Magnin; bag by Judith Leiber at Neiman-Marcus and Saks Fifth Avenue; earrings by Kenneth Jay Lane at I. Magnin; pumps by Vittorio Ricci at Saks Fifth Avenue and Bloomingdale's; panty hose by Givenchy at Woodward & Lothrop; Aris crushed leather gloves at Woodward & Lothrop. Center, his black tie by Gior9io Armani at Neiman-Marcus in October; men's evening pumps at Brooks Brothers. From Pinky & Dianne for Private Label, gray wool jacket with black velvet dots, black silk organza blouse and gray flannel pants at Marie Claire; earrings by Kenneth Jay Lane from Woodward & Lothropl bloves by Aris from Woodward & Lothrop; panty hose by Round the Clock at Hecht's; Daisy's open-toe pump at Garfinckel's.