Rachel Bilson has style all of her own. She knows how to dress every single time, wherever she goes and I can't say that I've seen her in anything horrible. She doesn't do anything over the top, and she keeps it simple and feminine.
In this picture, Rachel's showing off her long legs with this fabulous summer outfit. A pair of tight not-so-short but still short shorts, a white tee, a long sweater over, and a cute pair of shoes with a little heel. Absolutely perfect, in my opinion, and it looks great on her.
These shorts are very easy to work with because they're not super short, but they're also not bermudas- they're in between and that's what makes them so versatile. Of course, if you're not too proud of your legs don't wear tight shorts like that, but instead try something more loose.
The sweater over the outfit gives it a simple, comfy, look. It also makes the outfit look wearable pretty much anywhere, unlike other celebrity outfits.