ashgreene1_main.jpgThis weekend in the Hamptons, Ashley Greene showed up at a benefit for the Ovarian Cancer Research Fund with a shorter, just-past-the-collarbone haircut. Although most are suckers for long, flowing hair, I'm sure every woman adores the bounce and effortlessness of Greene's new length. So how do you know when you need a real haircut? Hairstylist Oscar Blandi explains the signs:

—"Your hairstylist cut layers the last time you got your hair cut, and now your hair is nearing one length."

—"You've had the exact same length for the past five years. To ensure your dead ends are gone, get a few inches chopped."

—"Your hair is looking thinner. The longer fine hair grows, the thinner it looks. A shorter cut can give you the appearance of thicker, healthier hair."

—"It takes you longer than usual to style your hair. When it never turns out the way you hoped, your cut is getting too long."