When it comes to facial hair styles, here is the guiding principle to keep in mind: Your beard and your jaw should work in tandem to achieve a nicely graduated, oval shape. If you have a square or round jaw, you’ll want to grow your beard fuller on the bottom to elongate your face. If you have an oblong or rectangular face, you’ll want more hair on the sides while avoiding more length beneath the chin.
Keep hair fuller on the chin, shorter on the sides.
Grow hair longer on the bottom, shorter on the sides.
Oblong or Rectangular Face
Keep the sides fuller, and the bottom shorter.
Oval faces are a middle ground between the other shapes, so most styles will work well.