Is your tween constantly clamoring for a Bratz doll, or a Nano, or whatever hot, new thing all her friends have (or so she says)? Don't despair: An obsession with trends isn't all bad. "It helps tweens identify with their peer group, which is part of a healthy separation from their parents," says Susan Bartell, a psychologist based in Port Washington, NY.

But setting limits is important, too. To do that:

Let her fund 'em. Have your child save her allowance or do extra chores to earn money for things she really wants, or at least ask her to chip in. She'll be choosier about what she buys if she's using her own cash.

Say no  -- and explain why. Veto anything your child wants to buy if you think it's inappropriate (say, low-rise jeans), even if she's saved for it. Just explain your rationale so she knows you're taking her seriously. If you're curbing your spending because you're trying to save for college or mortgage payments, let her know that, too.

Be a good example. If you buy yourself the hippest items the minute they hit the stores, it'll be hard to teach your child not to do the same. Moms with less willpower might show their kids a once-trendy, now-tacky purchase they've made (that Juicy Couture sweat suit?) as a cautionary tale.