Hairstyle is one of the important features that makes you look good. here are some tips I have searched on " how to select a hair style...
A Square Face:
Similar to the round face, keep the sides leaner and short, while wearing the top longer and styled a bit higher. Keep the hair clean around the ears and make sure the style mirrors the square shape of the face - this will help make the square face shape pop. Think of David Beckham. He got it right. Nick Lachey is another celebrity with a square face shape.
Characteristics of a square face: square jawline, almost as wide as long, straight sides, jaw and cheekbones the same width.
An Oval Face:
Most any style is suitable as this is considered the ideal face shape. That said, attention should be paid to other prominent features such as the nose and position of the eyes and ears. If you fall into the Oval category, consider yourself lucky as almost any style will look good on you. Actors with oval face shapes include Barry Watson and Jude Law.
Characteristics of an oval face: considered the ideal shape, slightly rounded jaw, no unusual characteristics (e.g. large mouth, nose or eyes), face shape resembles the shape of an egg.
A Long Face:
A style which is longer on the sides and short on top will make the face appear less long and provide better balance. Go with a cut that has some layers and is worn so the front hairline is disguised. A neatly groomed beard can help provide additional balance. Don't allow the facial hair to become too long as this will lengthen the face. Glasses can also provide balance by dividing the face and drawing attention away from the length of the face. Eminem and Keifer Sutherland are stars with long faces.
Characteristics of a long face: face longer than it is wide, often rounded jawline, cheekbones and jaw the same width.
A Triangular Face:
To balance out a triangular face shape, choose a style that will narrow your forehead area and add the illusion of width to the chin. An offset part with bangs swept to the side and a beard can help accomplish this. Justin Timberlake (who is a great example to follow) and Ryan Gosling have good examples of triangular shaped faces.
Characteristics of a triangular face: wide cheekbones and forehead, pointed chin.
A Diamond Face: For the diamond face shape, the goal is to minimize wider cheekbones and balance out a narrow chin and forehead. To do this, opt for a style with bangs to minimize the forehead. Longer shag hairstyles also work well for the diamond face. Famous guys with diamond shaped faces include Pete Wentz and Dane Cook
Characteristics of a diamond face: cheekbones are widest part of the face, forehead and jawline are narrow, long pointed jawline