1. SHOW SKIN STRATEGICALLY

Looking truly sexy involves knowing what to bare-and what to keep under wraps. Otherwise, where's the mystery? "Choose one-only one-body part and show it off," advises Jen Rade, stylist to Jenna Fischer and Angelina Jolie. "If it's cleavage, don't show your legs. If it's your legs, stay covered on top."

2. ROUND UP WHITE BUTTON-DOWNS

Take a classic cue from Marilyn Monroe! They elevate jeans and keep ball skirts from drifting into fantasy-land. But all that mileage comes at a cost: a short shelf life. So buy three, don't overbleach (which can cause yellowing), and refresh regularly.

3. ACCESSORIZE IN BRIGHTS

If you've got a closet full of neutrals-be they navy, black, camel, or gray-add energy with boldly hued shoes and bags. Not only is a hunter green satchel more lively than ho-hum black, but it's also surprisingly versatile. Feeling really brave? Wear a neutral base with shoes and a bag in two different complementary colors.

4. THINK IN MULTIPLES

Take a cue from Jackie O, who had a closet full of sheath dresses. If you find an especially flattering fit right off the rack, go ahead and buy doubles. When it works, why question it?

5. KNOW YOUR STRETCH

The secret formula for a soft but formfitting T? 95% cotton, 5% Lycra spandex. For jeans to hold their shape, they need at least 2% Lycra.

6. HEM YOUR PANTS FOR A SHOE HEIGHT
"The biggest mistake women make is wearing pants that aren't the right length for their shoes," says stylist Kate Young. To fix this, hem to either heels or flats like Emmanuelle Chriqui-no going back. Generally, hems should just graze the tops of your shoes and be from 1/2 inch to 3/4 inch off the floor.

7. THROW ON A SCARF

It's the ultimate accessory according to a host of the best-dressed women we interviewed. Stash one in your purse or carry-on to transform simple Ts in the time it takes to make a knot.

8. GO HANDS-FREE FOR EVENING

A dressy bag with a chain helps you hold crudités and a cocktail-plus, it lends a cool edge to evening wear, says stylist Cher Coulter. Wear the chain diagonally across your body for the best effect.

9. CONSIDER THE WEAR AND CARE

Before you buy, try to gauge how a piece might hold up after a few washings. And don't shell out for clothes you can't, or won't, take care of. If you know you'll never hand-wash that embellished sweater or fancy bra, walk away.

10. EMBRACE YOUR SHAPE

"Once you know which silhouettes flatter you, filter trends ruthlessly," says designer Shoshanna Gruss. For instance, if you're petite and shapely, it's best to avoid tall columns and billowy maxis even if you love them. Go for a dress with a defined waist and just-above-the-knee hem.

11. MAKE A LIST BEFORE YOU SHOP

Not of what you want to buy, but of the 10 fave items in your closet. This will help you zero in on pieces that mesh with what you own (or remind you that you never actually wear big floral prints).

12. HIT THE DRESSING ROOM PREPARED

If you're shopping for that ultra-important dress, get a true feel for the fit by bringing your hip or thigh slimmer with you. And while you're at it, bring heels, lipstick, and a hairbrush. These will help you get a better sense of the final result.

13. ALWAYS CHECK OUT THE REAR VIEW

And don't leave the house until you like what you see. Every angle matters. Trust us.

14. ROUND DOWN IN DENIM

When in doubt, go with the smaller size in jeans. They always stretch, and nothing's more unflattering than the unintentionally baggy derrière

15. EDIT YOUR CLOSET

Clothes need breathing room! You should be able to see every item without rummaging. Consider donating anything you haven't worn in the past year.

16. LAYER YOUR NECKLACES

Coco Chanel's more-is-more approach still makes a statement today. You can do multiples of the same material, or better yet, go for contrast: Try a femme piece with edgy chains, feathers with beads, or pearls with diamantés.

17. TOUCH THE INSIDE

A garment's lining is often a designer's calling card, and a good way to judge quality. A well-crafted lining is a sign that the whole piece has been sewn with care.

18. OPEN YOUR MIND

Always take one "it's cute but so not me" thing into the fitting room. You never know!

19. WHEN IN DOUBT, WEAR NUDE PUMPS

Matched to your skin tone, they're a pretty safe bet. (And they make legs look longer.)

20. WEARING WHITE? SEEK OUT LIGHT

Keep in mind: White clothes always look more see-through in daylight. Check yourself out in a bright setting to be safe, like Jennifer Hudson must have done.