The first thing a woman with a round face should look for is a haircut that accents length more than width. In other words, you want to stay away from haircuts that make your face appear wider, such as the short, classic bob cut to ear length. Any hairstyle that draws attention to the widest part of your faces is a definite no-no.
Depending on the texture of your hair, you may need to make use of styling products that add volume and shine to get the maximum mileage from the haircuts for round faces that you choose. Wearing your hair at jaw line length draws the eye down your face and is full at the crown creates a lovely frame.