The Round Face
When shaping the beard for a round face, go a bit longer at the chin to add length and make the face appear less round. Avoid bushy sideburns and keep the sides of the beard short. In lieu of a full beard, a goatee is often a good option for a round face.
The Long Face
Exactly opposite of the round face, the long face requires a beard which is fuller at the sides and shorter at the chin. The goal here is to add width to the sides and make the face appear less long. Make sure to avoid abrupt changes in length so the shaping is not obvious.
The Square Face
Similar to shaping a beard for a round face, the beard for a square face should be shorter at the sides and longer at the chin to add length to the face. Once again, a goatee is also a good option for men with square faces.
The Large Face
Since the face is large, any small facial hair or beard will appear out of proportion and make the face appear bigger. Keep the beard fuller and the mustache larger. Also follow the rules above for the appropriate face shape.
The Small Face
Small faces require small facial hair. Larger, fuller styles will make the face get lost and appear out of proportion. Also follow the rules above for the appropriate face shape.
The Oval Face
You lucky man! The oval face shape is considered the ideal shape and requires no special shaping to balance facial features. Do whatever you like and you'll look great.