Even if your mother was Sophia Loren and your father Johnny Depp, you can still improve your looks easily by learning what your face shape is and adapting your clothes, hair and accessories (such as glasses) to your face shape. The objective is to make the face appear like an oval and to minimise extreme facial shapes (diamond, round, square, triangle, rectangle, oblong).  To achieve such a well balanced illusion of the oval shape, avoid repeating extreme facial shapes.

For example: A round face will appear wider with a rounded hair style, round eye glasses and a round neckline or collar.

Look for contrasting necklines to balance your facial features, also keeping in mind other aspects of your body type (such as proportional shoulder size, height, etc).  Here are some guidelines to consider:

Oval: Maintain Balance
Hair:  Choose a simple style that complements your personality and lifestyle.  Style in proportion to overall body proportions.
Glasses: Any frame that also communicates the message your desire.  Your neural colour is most appropriate.
Collars: Choose to complement your neck, overall body size and professional or casual message. Traditional Collar >

Diamond: Narrow cheekbones. Add width to forehead and jawline.
Hair: Close-cropped at the cheekbones.  Fullness at the forehead high side part.  Fullness at back, below ears.  Add width by combing hair across forehead.
Glasses: Heavy frames across the top.  Straight sides on frames with the bottoms pointing down and out.
Collars: Avoid extremes, choose average length collars with slight wide spread. Wide Spread Collar >

Round:   Add length, slim.  Add angles.
Hair:  Add fullness on top, short around ears.  Side part, diagonally combed across forehead.  Angled, longer sideburns.  A beard with no curves appears angular.
Glasses: Slightly square frames, straight top.  Frame sides should angle in.  Avoid round or severely square angles.
Collars: Avoid extremes, choose average to slightly long collards with an average to slightly narrow spread V-neck jerseys. Narrow Spread Collar >