Use clippers and scissors to shape, with the goal of phasing out the clippers.
To grow your beard full and long, shape and trim it minimally, giving long periods between groomings. The goal is to groom minimally once a month exclusively with scissors, or with very little use of the shape-up clippers. In other words, the beard line on the neck and on the face should go as far out as the natural growth, only clipping a few stray patches that might be slightly out of line.
Similarly, after a few months, and especially years into a beard, you will find that a few snips with the scissors at the bottom of the beard and at the upper lip (if desired) every few months will keep a beautiful and shapely beard, that is, as far as beard decorum and shapeliness goes. A beard that is too short looks patchy, even if it's fashionable. I think it's a bad fashion, along the same lines of daily shaving.
Nota bene. Do not expect your beard to look like the hair on your head. It is a different type of hair, with a different thickness, coarseness and flow. Let it do what it naturally is inclined to do, the same as one normally does with the hair on one's head. You should not be cutting your beard more often than you go for a haircut. That would be excessive, unmanly.
