In the school of fashion, as we've learned from both magazines and mothers, there are in's and there are out's. Little black dresses: good. A black bra as your evening look: bad. Classic white shirt: good. A head-to-toe white outfit: bad (unless you're going to a kabbalah party). Louis Vuitton bag: good. Fake Louis Vuitton bag: bad.

We know these things deep down, but sometimes irrationality takes hold. Something grabs your fancy: the baggy plaid dress that reminds you of that amaaazing night at the Nirvana concert in 1990, the all-leopard look that is so Studio 54, the skirt that might be a little short — but short's cool, isn't it? How can it be wrong, you think, when it feels so right?

But it's not just wrong, it's a crime. So take these tips to heart unless you want to end up in an on-the-stand stare-down with the D.A. And unlike the guilty gal on this page, you won't have a chic orange Ralph Lauren ensemble waiting for you in the slammer.

ALL-LEATHER LOOKS

Yes, leather is