FROM THE SEATS near the front of the runway, we could lean forward and peer behind the screen to see the models before they came on stage.

We watched the young women line up - slipping into their shoes, arranging their hair, composing their faces, then stepping into the spotlight.And we watched Oscar de la Renta.

Like a weaver lifting a creation off the loom, like a painter choosing a frame for his latest landscape, de la Renta put the finishing touches on his art.

Gently, almost reverently, he helped one model arrange her hat. He snapped a bracelet. He fastened an earring.

He smiled into the models' eyes and spoke softly. He touched the sleeve of each gown.

He looked very proud.

This was his big week.

In New York, in the spring, journalists and retailers gather to see the best work of the country's best designers: the fall collections.

The mood is festive. The pace is exhausting. Every day, all day long, is like opening night at the theater. For a week, there are eleven shows a day, one every hour. There are parties every night.

Even though most designers were cutting costs this year - and only three held their shows at the traditional and expensive Plaza Hotel - the shows themselves are always dramatic.

Randolph Duke started his show with a smoke bomb. Joan Vass marched out red-haired models. Betsy Johnson held her show in a disco. Michael Kors held his, as he always does, in the loft of his garment district warehouse.

(Perhaps this year was his last at that location, since, mid-show, a huge light and chunk of plaster came crashing to the runway, just missing a model and the audience in the front row.)

In every show, the music is loud, pulsing. And, as if the lights aren't hot and bright enough, cameras flash constantly. The models stride to the beat, flipping their heads and skirts, posing, strutting.

The photographers call out comments. The audience bursts into applause.

At the end of the show, the designer comes out to bow. The audience crowds around clamoring compliments, but only for a moment. Soon everyone rushes off to the next show.

At the end of the week, looking back over several thousand ensembles, the overall impression is one of modern art on two legs.

For fall 1991, we saw rich fabrics, cleanly cut. We saw interesting texture and weave, and lots of gold embroidery but very few prints. We saw simple designs, plain little scoop-necked dresses in daytime gabardine or evening-wear beads.

We saw beautiful coats -- long and swingy or quilted and fat. In most shows, the coats and evening dresses were the most outstanding pieces. If you've been waiting to buy a good coat, one you'll like for years, you'll find it this fall.

Certain trends run through all the shows:

Short skirts. Though the products that designers eventually ship to the stores will be 3 or 4 inches longer, in New York this month the models displayed thigh-high skirts.

Skirts are wider than they were last year, however. These slip skirts, flip skirts and pleated skirts allow freedom of movement. They moved themselves, quite perkily, as the models strode forth.

Some designers, like Eleanor Brenner, offered a choice. Brenner showed suits with ankle-length skirts worn over flat sturdy-looking boots. A pretty look and a warm one.

Slim pants. Nearly every designer showed stretch pants, some with stirrups.

Tights and unitards. Charlotte Neuville wraps a coatdress over unitards. Jennifer George drapes a long knit sweatshirt over tights.

Pastels. Picture peach, violet and palest yellow. Picture Richard Mishaan's blazers over slim pants and Randolph Duke's hooded coats over stretch pants.

Plaids. As in Arnold Scaasi's bright dresses and Oscar de la Renta's bold-to-the-point-of-garish suits. As in Adrienne Vittadini's magenta and gold plaid jackets and pleated shirts. As in Isani (which is what the brother-sister team of Jun and Soyon Kim call their line) pale 60s-style suits.

Knits. As appealing as her muted sweaters are Joan Vass' knits. She showed menswear patterned after her women's line. Men look good, even suave, in jackets and slacks that move as they walk. They look comfortable, too.

Other nice knits? Those by Rebecca Moses and Jennifer George.

Elegant coats. Calvin Klein show sharling and cashmere. Norma Kamali has a reversible fake fur. Eleanor Brenner shows some fox trim. No one is showing fur coats this year.

They prove that leather can be just as pretty. Donna Karan produces a shiny gold seude bomber jacket. The suede is washed somehow; it's soft.

And Michael Kors' full trench coats in petal pink and bone yellow look soft too. They move like silk. At $3,000, they'll sell for less than fur.

Zippers. Instead of jewelry, zippers. They zig-zag across the bodice of dresses and jackets and shine on pockets, sleeves and pant legs.

Red. Bright and solid. Bob Mackie's models bounced down the runway to the strains of "Too Darn Hot," wearing an embroidered tuxedo, a Lycra catsuit, a fringed halter minidress, a strapless satin evening dress and a dozen more.

Chocolate. Some call it "bittersweet." Some call it "cocoa." But brown by any other name still shows as strong. Geoffrey Beene showed brown tweeds.

Black. Donna Karan showed it best. In dress after dress, in jersey and wool, black never gets old. Especially with gold.

Shimmering evening wear. Like the sequined art deco jackets by Bob Mackie. Like Oscar de la Renta's gauzy, gorgeous jacquard lame jacket and pants. Like the organza skirts on Carolina Hererra's black evening dress which begin high above the knee and trail behind in ripples to the floor.