One way to find out whether or not a pipe flatters you is to pose with it before a mirror. Try on the pipe as you would try on a hat or an overcoat.
If the pipe looks out of place in your mouth, put it back on the shelf.
Generally, a tall slender man looks better smoking a straight, long-stemmed pipe, such as the lumberman or billiard. Short, plump men, with rounder faces, look more natural with curved pipes such as the bent or Oom Paul. But the ultimate choice is up to the smoker, whose own taste should guide his selection.A big man, over six feet tall and weighing two hundred pounds, would look ridiculous smoking a midget briar. On the other hand, a small skinny fellow has no business smoking a pipe nearly as large as his face.
From Weber’s Guide to Pipes and Pipe Smoking