Everyday underwear

This is your core lingerie—it doesn't shift around, it doesn't show, and it's comfy enough to handle eight hours plus at your desk. It should include plenty of black, white, and nude bras and panties—not too skimpy and preferably seamless. But Susan Nethero, chief fit stylist for Intimacy boutiques, urges a revolt against purely functional styles, suggesting richer colors, witty prints, even lace and embroidery.

Above: Start fresh with easy-care, hard-wearing whites: an immaculate underwire bra and teeny bikini.
Workout underwear

Like free weights or yoga mats, gym-friendly underwear is essential equipment. But don't shop for sports bras where you get running shoes, Nethero says: Those sold at athletic stores often compress breast tissue (unhealthy). Buy bras with cups—and, if necessary, underwire—plus thin seamless panties. Moisture-wicking fabrics no longer have that nylon-y feel, and boy, do they keep you cool and dry.

Above: Get going with a well-engineered bra with two-ply cups tops tiny shorts with built-in mesh panties.
Evening underwear

When considering underthings for nighttime, the challenge is making sure that your choices stay invisible. "You don't want to plan an evening in a killer dress only to discover at the last minute that you have nothing to wear under it," says Nordstrom's Sandra Saffle. Be prepared with a convertible bra that adapts to all necklines, including strapless, plus a few lightweight shapewear pieces to address any excess.

Above: This smoky mauve lace bra dips low, so it won't show under the scoop-neck dress she's about to zip up.
Sexy underwear

Racy lingerie, frankly, can make some of us a little nervous—but maybe that's the point. "It's fun to explore something that pushes your boundaries," says Jennifer Duenas, former associate store manager for Kiki de Montparnasse, known for its risqué wares. Most of these flimsies are for (very) private consumption; with today's trend toward taking lingerie public, though, you never know.

Above: This lavish set is sized for the amply endowed.