For their new T-shirt-of-the-month venture, Stylemint, Mary-Kate, and Ashley Olsen are wielding their very best marketing tool: themselves. But they're also enlisting their trendy friends to serve as "guest editors," since we all need as much help as we can get to make our T-shirts look fresh and different every month. First up is stylist Sara Moonves, who apparently goes way back with the Olsens ("we grew up in L.A. together," she explains). Watch them giggle amongst themselves, discuss the finer points of white pants, and give styling recommendations in their debut video.

[Stylemint]