NEW YORK -- The holidays are often a highly social season that provide a good reason to wear the things you might not often have the occasion to pull out of your closet: sequins, a fancy red dress, the sexy black one.

But should you? Or will everyone else be wearing their cozy cashmere sweater and favorite riding boots?

"People don't know how to dress anymore -- it's anything goes, which is a huge problem," says Marie France Van Damme, a fashion designer and author of the new book, "RSVP: Simple Sophistication, Effortless Entertaining." "People are either overdressed or not dressed at all. They should be looking for the happy medium."

The invite -- or the more likely Evite -- probably won't give you the guidance you're seeking. Hosts want to kick off the party with cute conversation, not an edict about what to wear. And even if dress code is addressed, it's probably "cocktail casual" or "holiday glam," which can mean a whole lot of things to different people. Even the formal "black-tie" directive seems to be open to interpretation.

"As soon as you get an invitation, the first question is, 'What do I wear?' Or at least that's what I think," says Lisa Axelson, head designer at Ann Taylor.

Style expert Amy Tara Koch goes straight to the fine print to see what the venue is. She says that gives the biggest clue; a party at someone's home will dictate a different dress than one at a restaurant.

A house party gives permission to be a little more daring, whether it's a plunging neckline or a fashion-forward combination, mostly because there's an assumption that you know the hosts well enough to be invited into their inner circle and you could very well know the other people there, Koch says. A restaurant party could still be a gathering of your more intimate friends, but it also could be with work colleagues or extended family -- you know, the relatives you only see in December.

Axelson, however, sees a big difference in the appropriate attire if the party is at the country club or the neighborhood bistro. She also lets the day and time guide her: probably nice trousers or a pencil skirt and embellished-neck sweater with flats for a Sunday brunch, maybe something with some glitter for Saturday night.

An afternoon open house is practically an invitation for something colorful, says Koch. Her plan this season is to break out a bright shirt, fur vest, leggings and tall boots.

There are very few dress-code mistakes that can't be fixed with a great shoe, says Colleen Sherin, senior fashion director at Saks Fifth Avenue. The other option is a lovely necklace or earrings to draw people immediately to your face.

Both Axelson and Koch encourage easily removable accessories that dress up or down an outfit. It could be the statement necklace that tucks under your collar if it's a more relaxed crowd, or a beaded wrap or tailored jacket -- maybe one with sparkle, Axelson suggests -- that can be hung with the coats if needed. No one will be the wiser, they say, and you'll walk in knowing you have options.

It's not a bad idea to keep "a few spare parts" in the car as well, in case you've shown up on the casual side, says Koch.

"My transition toolbox is textured tights, long dangling earrings, a very long, vertical scarf, a cuff bracelet and a brighter lipstick," she says.

Van Damme purposely carries a clutch to parties, which blends better than a big overstuffed handbag, so she can slip things in or out without drawing attention.

She'll always choose a sleek and chic silhouette over something froufrou -- it's respectful and stylish, she says.

Generally, Axelson thinks separates, cigarette or dark denim pants with the pleated or slinky tank and cardigan, for example, offer more flexibility. "With a dress, once you've made a commitment to it, you are staying in it."

What about brocade or jacquard skinny pants with a great blouse? You'll probably feel comfortable in it and treat walking into a party like you were stopping into the corner place for coffee, Sherin says.

But Van Damme puts her foot down on denim. "I don't think jeans are right for a cocktail party or most parties -- maybe with a fabulous, fabulous top, but why not put black pants on instead?"

No one is going to the trouble of hosting a party for guests to look like they just rolled out of bed, she says.