Celeb: Penelope and Monica Cruz (here in some chic black looks from their line)

Fashion Line: MNG for Mango

Qualifications:The Cruz sisters' main qualification for designing their line for Mango? Amazing wardrobes. The collection they created for the giant Spanish chain store was based on vintage pieces they already owned.

Celeb: Sarah Jessica Parker (in an adorable Bitten sundress)

Fashion Line: Bitten for Steve & Barry's

Qualifications: Growing up on a shoe-string budget in real life and spending six years in Carrie Bradshaw's Manolos has made SJP a master at combining high and low. Trust us, you'll never find a better way to spend $20!

Celeb: Rachel Bilson

Fashion Line: Edie Rose for DKNY Jeans

Qualifications: This ex-OC star is famous for her eclectic style, so we're sure her new line, inspired by her own wardrobe, will be a winner. But don't bet on Bilson getting her hands too dirty. "I can't draw at all, so I won't be doing any sketches, but I am learning to sew. I think it's important to know more about the whole process of making clothes."

Celeb: Ashlee Simpson

Fashion Line: T-shirts for Wet Seal

Qualifications:The mom to be is passing along her punky, casual style to her young female fans. "I was inspired by so many fun, wonderful things as I was recording Bittersweet World -- it's been great to carry through those inspirations into these new shirt designs," says Ashlee.

Celeb: Natalie Portman

Fashion Line: Té Casan

Qualifications: Harvard educated Natalie's leather- and cruelty-free shoe line was inspired by her love for fashion -- and animals. Her chic sense of style is definitely a hit: she was booked as the celeb judge on the latest Project Runway series.