As if Sienna Miller doesn’t have enough to brag about – she’s been in four movies just this year (Stardust, Camille, Interview, and forth-coming The Mysteries of Pittsburgh), and has three already lined up for next year – she recently launched her own clothing line. The label Twenty8Twelve (named for her birthday) is collaboration between Sienna and her sister, Savannah Miller. Unlike some stars who jump on the designer bandwagon with little experience, Sienna was wise in enlisting the help of Savannah, a fashion designer by trade.

The preview of the line featured pieces for next spring. That’s pretty forward-thinking – it’s difficult to predict where the fashion trends will go almost a year down the road. Maybe for that reason, Twenty8Twelve’s Spring ‘08 collection plays it pretty safe – featuring the ever-popular nautical colors blue and white, classic trenches, and good old stand-by babydoll dresses.

Which makes it kind of ironic that the sisters say they intend the clothes to speak for themselves, since - according to them – celebrity fashion is too generic and dumbed down. That’s not to say the line isn’t adorable. And you do have to hand it to the girls. Considering neither of them have stylists, and considering all the trends Sienna is credited with starting (thank her for those skinny jeans hanging in your closet. And those slouch boots. And … you get the picture), they’re definitely doing something right. They both have a good finger on the pulse of the styles people want to see.

Besides their relationship with fashion, the sisters keep close tabs on each other too, which has made working together natural, says Sienna.

“If I find something in a thrift store in some weird town that I’m shooting in, I show it to Savannah on the Webcam. I can say stupid words to her about clothes that other people wouldn’t understand. She gets it. We’ve worked really hard. This isn’t about just lending a name to something and not really being involved.”

The Fall collection will be available exclusively at Bergdorf’s in New York, Neiman’s in Los Angeles, and Holt Renfrew in Canada. Look out for printed silk dresses, denim jeans, cotton tees and tanks, tailored pants, cropped tuxedo jackets, canvas trenches, and leather bomber jackets.

-Alexis James