Voted sexiest in her senior class, Bilson, 25, a star of FOX's The O.C.
, figured out her formula early on and stuck to it
DRUGSTORE DEAL: 99¢ wet n wild white eyeliner. "I've always used wet n wild! A light liner on the inside of your eyes really opens them up."
TRIED AND TRUE: "I shop at Sav-On a lot—Lip Smackers and Maybelline mascara."
DIY BEAUTY: "The Emmys was the one time I had my hair and makeup done. I do it myself almost all the time." And she avoids spas. "The only time I got a professional massage, I was nauseous."
BIGGEST DON'T: "The brown lip liner with pink lipstick phase in junior high."
COMES WITH THE PACKAGE: Boyfriend and costar Adam Brody "loves my freckles."