Part She-rah, part He-man, the dress over jeans look gives a girl the best of both worlds: edgy comfort and sex appeal. Former Dark Angel star Jessica Alba rocks the look with sheer hipness by pairing a not-so-formal black strapless dress over dark, skinny jeans. While you don't have to be a celebrity to pull off this trend, you do have to be smart about how it's worn. The length and make of the dress, as well as the fit of the jeans, should vary according to one's size. If you're petite and curvy, stick to a short, umpire-style dress over slim-fitting, darker jeans. The more leg you show, the taller you'll seem. Plus, dark denim also helps make anyone seem long, lean and leggy.