Free -Spirited: 20s.(fashion)(Buyers guide)

Byline: TABITHA SIMMONS Photographed by Craig McDean.

As far as TABITHA SIMMONS is concerned, the only rule in your 20s is that there are no rules. It's the time to mix it up and make dressing personal.

When I was in my early 20s, I was working as a model, so my style was about the ultimate freedom of living out of a suitcase. That kind of experience might not seem relevant when you've just graduated from college and are about to embark on your career, but in a way it is: This is the time when you're going out and having fun, and chances are you don't have the responsibility of kids. The way you put your clothes together should reflect the freedom you have, which means you can totally blur the distinctions between day and night, new and vintage, dressed-up and dressed-down, inexpensive and designer. It's that eclectic, anything-goes, make-it-your-own attitude that was so important to this story. (Mary-Kate and Ashley Olsen do it brilliantly.) One thing that is really important is not to feel that you have to spend a huge amount of money on what you wear, which is why the fashion here comes from labels like H&M, Topshop, French Connection, and A.P.C. You can always work in the occasional pricier piece, like the Junya Watanabe cape; I am obsessed with capes right now. Or you can invest in an expensive accessory--a Lanvin belt, a Tom Binns cuff, an Alexander McQueen purse--that you will wear a lot, making you feel like you got your money's worth, and that upgrades everything you wear it with. One last thing: Embrace going short or tight. Nothing has gone southward yet.

"Go for the really short, really layered look--you're young enough to get away with it"

For more editor-inspired ideas on how to dress for every decade, go to Vogue.com.

CAPTION(S):

SONG OF MYSELF Maryna Linchuk dresses in Simmons's style, with an unusual piece like this kimono, a pastiche of prints, and a wide belt, which "gives things a more upscale look." H&M embroidered-silk kimono, $149; hm.com. French Connection floral-print dress, $178; Bloomingdale's. Subversive Jewelry by Justin Giunta necklace. ...