Did we mention that you should never look like you tried too hard? Ms. Pompeo's fifties style suffers from a case of over-teasing, over-doing it and just plain going overboard. As a general rule, if you could successfully hide a hamster in your hair, you've gone too far.

Behold the Queen of Retro. Von Teese has made her fortune as a virtuoso in vintage goodness. While she may do more than hint at the past with her look, she knows what looks good on her and sticks with it. The secret is to create a retro look the way it should have been, not the way it really was. This was a great week in hair for Dita and other celebrities.

Proof that anyone, even the Queen of Retro, can goof it up. That's how treacherous the retro path can be. Retro styles threaten to age the wearer and look matronly rather than glamorous. It's always better to dial back and modernize a bit. This look is more Mrs. Cleaver than Betty Page.

This is one of the most memorable retro looks ever worn by a modern celebrity. It's vintage yet modern and perfectly executed. The accompanying makeup is spot-on, and it goes perfectly with Klum's gown. And it was easy (albeit expensive) - Klum just popped on a custom-made hairpiece. See more Heidi Klum hairstyles.

While the amazing Ms. Klum rarely flubs, here she missed the mark. This sixties-inspired updo is so over-worked and glazed into place, it looks like a petrified bale of hay. It's downright intimidating. If your hairstyle can be used to break open walnuts, you've gone too far.See more Heidi Klum hairstyles.