From PEOPLE Magazine Click to enlarge
IN YOUR 20s Short Shorts
Christian's Pick

BLAKE LIVELY
"To pull off dressy shorts, they need to be interesting. The look should be youthful."

AMBER TAMBLYN
"These shorts are a bad length—and the cardigan is longer!—so they're not flattering."

IN YOUR 20s Maxi Dress

KATIE HOLMES
"It reminds me of the muumuus my mom used to wear around the house. It's so shapeless."

Christian's Pick

CHERYL BURKE
"Without a grandma cardigan, it transforms the look—and the bright color is more youthful."

IN YOUR 30s A Mini

MARIAH CAREY
The too-short mini and cropped top "look very dated. She has a great figure, but this is not the way to show it off!"

Christian's Pick

JENNY McCARTHY
"A fitted dress that hits just above the knee is just as sexy as showing skin, but it's a classier look."

IN YOUR 30s Cocktail Dress

Christian's Pick

EVA MENDES
"Choosing a dress that's fitted at the waist and hits at the knee makes a huge difference."

KATHERINE HEIGL
"It's a little long. And the pearls look like they're from an old lady's estate sale."

IN YOUR 30s Bubble Skirt

Christian's Pick

JENNIFER CONNELLY
"Bubble skirts should be a little longer and nipped in—it's not a big tutu."

GABRIELLE UNION
"This is too mini, so it looks like she's trying to look younger."

IN YOUR 40s Florals

VIRGINIA MADSEN
"It looks like a pillowcase print. And I hate that pink belt—so bad! It cuts her off funny up top."

Christian's Pick

KRISTIN DAVIS
"A cap sleeve looks great if you don't have much shoulder," says Siriano, who also praises the belt.

IN YOUR 40s Satin

Christian's Pick

DEMI MOORE
This cobalt blue dress works because it has "some shape, so you really see a waist."

MARISKA HARGITAY
With its two-tone color pattern and loose cut, this dress does "nothing" for her figure.

IN YOUR 50s Leopard Print

Christian's Pick

CANDACE BUSHNELL
"Do prints like this small. Neutrals and a leopard-print clutch? Gorgeous!"

SHARON STONE
"You want to wear a leopard gown? You should be in your 20s on The Hills. At this age it's too trendy."

IN YOUR 60s Casual Chic

GOLDIE HAWN
"The layered tank tops are frumpy. And cowboy boots make it look like she's trying to be cool."

Christian's Pick

JACLYN SMITH
"A fabulous flat is so much better! And as you get older, fit is the most important thing."