"That's where it gets hard to put into words. The best I can give you is a visualization technique, I think."

He sits in a chair, stretching his arm out on the tabletop, and makes another shallow cut with the scalpel, using the kerchief to blot up blood. It takes a little focus to keep himself from healing instantly. "Right. Instead of letting the normal clotting process occur, try to picture the severed blood vessels. Imagine the bleeding ends closing. Pinching or constricting. If the full level of anatomical detail is too much to hold at once, simplify it and just picture, I don't know, tubes or pipes."