Dan,
A problem to be sure. There are many out there that are much better trained in this area than I am, Basham, Kidwell, Turner, etc. AND many "volumes" written on the subject. But since you asked me, here goes -- Arne's "take."
TP manifests itself in many different ways, but the most common seem to be releasing too soon (or uncontrolled release) and freezing up. All, I believe, are a result of thinking about the wrong thing at any given time. I am personally convinced that we need to shoot a shot sequence that is "thought out" consciously and step by step. The subconscious is a strong tool but it is also lazy and tends to want to skip steps.
Before anyone jumps in and starts the "I shot this deer and don't remember anything until the arrow hit" discussion; I'd point out that this is NOT related to hunting or application, but a TRY at getting control of the shot --relieving TP. Hunting and proficiency come later.
List your steps of the shot sequence -- write them down and post where you can see them as you shoot. Stand in front of an "arrow catcher" (blank bale -- NO TARGET!!!!). Now run the shot sequence as you perform them -- might take a light weight bow initially so you can take your time following the steps! Speeding up will come with repetition and eventually you'll have the "sequence" memorized and won't need the printed list.
Think out EACH step -- EVERY TIME. It might look like this(only a suggestion you have to build your own sequence):
1. set stance
2. set posture
3. nock an arrow
4. set string hook (hand/fingers)
5. Set bow hand (grip)
6. lift to draw
7. Draw
8. Anchor
9. ( )
10. release
11. follow through (and evaluate final position)
Do NOT rush this, don't get lazy, Think EACH step EACH and EVERY TIME!!!! Take your time with each shot too!!
Many will also say that "blank bale" is not a fix for TP. In and of itself, it is not. What YOU do at the blank bale may be though.
Conscious execution of the shot steps EVERY TIME!!! I feel you must train yourself to think only about the steps of the shot. When a person only thinks about the target AND that is their full and only concentration, the subconscious takes control of the steps of the shot and will frequently try to "hurry" or "shortcut" the steps. It will try to jump directly to the release ('cause I'm on target)or start jumping around from target to execution to alignment to you name it, which causes total confusion and a "OH just get rid of the arrow" or a freeze up because the body is getting too many instructions too fast and ends up not knowing what to do, so we don't do anything.
The subconscious is NOT your friend here. Your conscious mind is your friend because YOU control it with direct thought.
SO, a person must get control of the shot as a first step in defeating TP. It will take a lot of time and patience on your part simply because you didn't develop TP overnight, it built up over a period of time. It will take time to be able to control the shot mechanics. Here, standing VERY close to the bale and closing your eyes for the entire shot may help too.
Now, notice the step #9 I have above. Guess what goes there. That's right, aiming. I for one do not, will not, and never will advocate aiming ANYWHERE in the shot sequence until AFTER ANCHOR!!!! You do "orient" yourself to the target but that is not "aiming", IMO. At that point #9 (if you will) you consciously set your aim (by WHATEVER METHOD YOU use!) Then that one step and only that one step is passed to your subconscious And YOU CONSCIOUSLY move on to thinking about step 10. Your subconscious will hold the aim you set so forget it and move on to consciously executing the rest of your sequence.
The arrow hitting the target is a FUTURE event! YOU cannot control the FUTURE (no matter how hard you concentrate on it)! You can only set the best situation possible in the PRESENT to ALLOW a good future outcome. Execute consciously in the present, the future will take care of itself.
Work the CONSCIOUS shot execution at the bale, or in pilot jargon, run the checklist. DO NOT "check" on your progress by seeing if you can hit a bull's eye, for a good long while. Yes, this will become boring, and you will start to feel stagnant and your curiosity will try to make you "check" on your progress. DON"T DO IT!!! Can you say, "instant relapse?"
An arrow in the bull's eye is NOT a measure of progress! Your measure of progress IS YOUR self analysis (be brutally honest) as to whether you executed a good shot. Even a bull's eye can be a mistake so that is NO measure!!
Once you have gotten to a place where YOU feel you have control of the shot, then and only then you start a "bridge" program. But that is for later and another discussion.
Well, you asked. :D
Hope this gives you some "food for thought" and maybe a start at a remedy.
Arne