Pinch method is a way to attach materials to the top of the hook shank. I had a great amount of difficulty understanding this until I read an explanation by I think Skip Morris. Here's my best shot.
Pinching the material to be applied between the thumb and index finger align to the top of the shank. Bring the thread up between the material and thumb tightly and pinch tight. Bring the thread down between the material and index finger and pinch tight. You should now have thumb, thread, material, thread and index finger pinched tightly and held directly on top of the position you want to apply it with the thread on the far side of the shank. Pull down sharply and firmly and the materials should be directly on top. Sometimes I'll start with the material just slightly to my side and may be a good place start.

Peter