Heart shaped faces are widest at the temples and narrowest at the jawline. Keep top layers soft and long. Square faces have a square jawline and hairline at the forehead. They are 'too short', so a suitable hair cut style seeks to create height elongating the face. Diamond shaped faces are widest at the cheekbones and narrow in the forehead and chin. By creating width at the forehead and minimizing it at the cheekbones, the illusion of an oval face can be achieved. Pear shaped faces have a narrow forehead and are widest at the jawline, with a round chin. The objective of a suitable style of hair cut is to give the illusion of an oval face by creating width at the forehead and temples. The oblong face is generally described as having a high forehead, narrow bone structure and long, well defined chin.
If your face is oblong, then the goal is to balance out the length of the face to make it look more proportioned. Rectangular faces have a square chin and hairline, and are long and narrow. The ideal style of hair cut is one which creates width at the sides disguising the narrowness. A fringe can also shorten the face, and a style with a side part will help to reduce the square appearance. Diamond face shape is a cross between heart and oval. If you are a true diamond, you'll be able to wear almost any style. Try hairstyles with lots of fringes, chaotic yet sexy and defined curls, chin-length bobs and shoulder length cuts with feathered edges. If you need to add fullness in order balance out your shape, going with thick layers or a bob of medium length, making sure the fullness lands where it is most needed, is your best bet.
Source : http://ezinearticles.com/?Most-Flattering-Hair-Style&id=820869