Same here. The further the distance the worse my TP was. I’d shorten my draw focusing on the target. I got over it by the doing what others have suggested coming to full draw at various distances, holding draw and letting down. Then after getting comfortable coming to full draw shooting one arrow then doing it all over again. I guess focusing more on the draw and anchor instead of the target helped me. Oh yea…I keep tolled up TP in my pocket too. For emergencies and marking blood trails.
I think this is a good method for those situations where you have the time to do it. Fortunately, I’ve never had this problem when shooting at an animal. My TP rears its ugly head when I’m shooting repetitive arrows in a group, like in a 3D tournament, or even just informally. The greatest problem I had was forcing myself to do the things you suggest while other people were watching me and waiting for me to shoot. Finally I just decided that I really had no alternative, since jerking the release on a partially drawn arrow was unacceptable, and I would prefer quitting than to continue to do that. So the other people just have to put up with me drawing and letting down, etc. Frankly, I think we worry too much about what other people might be thinking, because the truth is, they're probably not thinking about us anyway.
But to return to the original question, how do we control TP when we only get one shot, and there is no time to wait or to do practice draws? I really have no good answer to that, other than the one offered several times already, which is to attend Joel Turner's course, either on-line or in person.