Short 'dos with mega volume are awesome for adding the illusion of length to your round face. You can pump up the volume in just the crown area or all over the top of your hairstyle; both options work wonders. This type of hairstyle includes a short and spiky hairstyle, if you have the type of hair that will take a stand without much fuss. What you don't want is to add any volume at the sides of your hairstyle. Keep this area cropped short or tucked behind your ears. Also, don't go extremely short with your hairstyle (like buzz cut short). That's too short to counteract anything, and you'll just end up looking like one big round head.
Long and Sleek
By contrast, a long and sleek hairstyle will counteract the roundness of your face. This hairstyle fools the eye by essentially “trimming” away at the width in the side area of your face. Long, face-framing layers styled toward your cheeks add to the illusion and act as an instant face slimmer. A middle part in this hairstyle will work well; if you insist on bangs, make sure they are kept long and swept to the side. A bold or blunt bang slammed down on your forehead will only make your face look shorter and rounder.
Although a round shape is certainly a tribute to symmetry, it's a good idea to try to mix it up a little. A funky way to do this is with an asymmetrical haircut. Think short and cut above the ear on one side and a bob hairstyle that sits about an inch below the chin on the other. It's bold, sure, but it's going to trick the eye into seeing two very different halves of your pretty face and ditch that boring roundness. The lengths you choose for each side can vary. The more drastic the difference between the two, the wilder the hairstyle, and the more it draws attention away from the round shape.
Bobs Below the Chin
The bob is a classic hairstyle that's survived through many decades because it's easy to maintain and comes in so many variations that you can find one to suit just about any hair type or face shape. You gotta love a hairstyle like that! For a round face, the one golden rule is to keep the length of the bob below the chin. This is done to draw the eye past the end of the actual face and to create the illusion of length that's not really there. To have your bob stop dead at your chin would be like putting up a neon sign that read, “Look at my round face." Not really what you're aiming for, is it? Keep it between chin and shoulder length, and it'll do wonders.