The look -- polished; the options -- many

The fact that fashion has zeroed in on the waist this spring does not signify that every woman who cares how she looks has marching orders to get into a five-inch-wide cinch.

If she likes the idea, fine. More power to her. She'll be right in the mainstream. If she doesn't like it, that's fine, too, because the days when a woman felt impelled to dress in a stated way each season (or be looked down on as impossibly out of it) are over. What we have today is the era of freedom of choice. Ranges of styles, otherwise known as ''options,'' are the general rule.

Thus designers in their wisdom have also remembered the woman whose beltline looks better when it is anchored around her hips. And for women who prefer no belt at all, the loose and easy blouson and the chemise are still in the fashion picture.

What is really new this spring, what came along as a side effect of the trend in Europe and America toward more fitted clothes, is a change in attitude. There is a higher degree of formality in dress, a closer attention to detail.

The suit, which is back in force and which could well be the mainstay of a career-woman's wardrobe, is worn with a hat (a straw boater, preferentially), a lace handkerchief in the breast pocket, and gloves. The casualness of sportswear separates is being relegated to off-hours occasions - like weekends - where it originated in the first place.

So while individuality is recognized, clothes are expected to be appropriate for their time and place, and to be thoughtfully accessorized. This is fashion's way of bidding farewell to the last lingering vestiges of the protest dressing of the 1960s.

Although options are plentiful (skirt lengths, for instance, vary from way above the knee to mid-calf), they are not unlimited. There are, as usual, certain looks that predominate and certain trends that are hot, as they say.

Black and white is definitely the color combination of the season - often pepped up with a shot of red. Suits, as noted above, are back in a big way, and a super selection of them has already arrived in the stores.

The dress, which has been gaining converts lately, is also on hand in abundance. The assortment includes shirtmakers with short puffy sleeves, bateau-necked two-piece fluid styles, fitted numbers with twirly skirts, and the tailored side-wrapped coat dress, a comer to watch from now on into fall.

If carefully shaped fit strikes the customer's fancy, this is her season. Many designers here and abroad have endorsed silhouettes that outline the bosom, the waistline, and the hips. This has resulted in a backward glance to periods when leg o' mutton sleeves, hourglass waists, peplums, and bustles were de rigueur. Fashionable New York women wore bustle taffeta gowns to gala parties this winter and added pearl dog collars, a fashion picked up from Britain's Princess Diana.

Eschewing the term ''bustle,'' designer Adolfo showed what he calls ''little tie-on poufs'' with his short evening dresses for spring and summer. The poufs, which are part of a sash, have floating streamers attached - a hint of a train. Being removable, this arrangement settles the question of how you sit down without crushing your bustle.

The peplum, another throwback to other times, is further evidence of back interest in current fashion. It flares out over a tight straight short skirt as a rule. The look is more 1950s than turn-of-the-century.

Speaking of the nifty '50s, they have been plumbed for a vast array of updates. Aimed at a customer too young to have rocked to Chubby Checker or Dick Clark's ''American Bandstand,'' the fashions are vervy retakes of camp shirts, Capri pants, circle skirts, low-backed halters, and strapless starlet dresses from that decade.

Ponytails and pompadours are the requisite hairstyles. Both Macy's and Bloomingdale's in New York have devoted special junior departments (Bloomingdale's is called ''Remember Marilyn'') to this escapist form of dressing.

For the romantically inclined, the season's offerings include scores of white and pastel cottons and laces. Linens of all kinds - handkerchief, homespun, jacquard - and cotton damasks are particularly strong, and seersuckers and other types of crinkly textiles have been used in quantity.

There is lots of sheer linen, delicately embroidered and inset with lingerie lace touches. Lace is, in fact, especially noteworthy this spring. Those who love it can literally dress in lace from top to toe, starting with a loose pullover top and finishing off with textured lace stockings - and even lace shoes. Bands of Chantilly trim both silks and wool challis dresses in the Geoffrey Beene collection. Another advocate of plenty of lace is Oscar de la Renta, who has used it for lavish borders.

Some linens and laces have an old-fashioned air, but there is far less of the fussy Victorian look around this season. The purer and simpler approach is more timely now.

Modernists who like their fashion clean and spare are by no means left out of the current fashion spectrum. ''Pure and simple'' are the watchwords for an important segment of the current mode. Architectural dressing, as propounded by Ronaldus Shamask, the Dutch-born designer whose geometric folds and seaming are at the opposite pole from the wasp-waisted genre of fashion, fills an important niche.

Then there is Zoran, the minimalist whose unadorned styles are the essence of simplicity and should not, he insists, be worn with jewelry. The well-worn ''less is more'' adage of Mies van der Rohe remains valid, it seems.