For instance, men who have a round face can keep a beard to create an illusion of an oblong face. However, do consider your face shape and hair growth pattern.
If you have a small face, a full beard must be avoided at all costs. You could sport a goatee or a chin strap. If your face is square-shaped, then you could keep a beard that is somewhat rounded, but avoid side burns as they will accentuate this face shape. So, select the style that is best suited to your face shape.
If you have a full beard, then trim your hair with the scissors first. You can get it done by a barber also. If you need to shape it more, then use the beard trimmer. It's always best to begin trimming just below the ear and then trim along the jawline. Thereafter, you could start trimming under the chin.