It seems all my cardigan baby sweaters tell you to yo, k2 tog to make a button hole. I end up with a hole rather large for a baby sweater sized button, and it is not a real neat look either. Usually these are sport weight or worsted yarns.

Short of buttonhole stitching around the hole with thread (which I have done every now and then), what is the best way to make a nice, tighter buttonhole?