ORIGINAL: gibblet
there are a couple schools of thought. push and pull seems to work pretty good w/ triggers, but i can now shoot an index trigger w/ back tension w/out pushing or pulling. i'd say that 99% of the time the issue, no matter which school you come from, is that you've got the wrong muscles tight. you have to learn to relax everything you're not using. you also have to have the bow fit you just right. if you're chicken-winging your release arm you're too short, and if you've gone past the line of your arrow w/ your release elbow you're long. your neck needs to be straight up and relaxed. if that muscle that goes down the right side of your neck is tight from tilting your head - back tension doesn't work. it needs a clear and relaxed line of travel to your rhomboid - or your rhomboid won't work. check your tricep for tension, and your forearm, and your fingers, and your shoulder. tension in them inhibits back tension. if you can get a little bit of a feeling like you're hanging when you're at full draw - that's the right place to start executing your shot.
i guess in one school you load up tension on the system and pull thru it, and in the other there is no added tension to the system at all.
if there's any way you could get w/ someone from any of the schools of thought, who's good at it, i think it would help you a lot.
I really agree with what John has said here except I am not from the school of thought that endorses push/pull.
No matter what technique you use, it is all about holding the tension to execute a shot in a part of your body that allows execution to be extremely consistent. Head position is a huge part of this, if you are not completely vertical with your head position it is difficult to hold the tension and execute a good shot in the proper places. Because of how short and compact your rhomboids are, they are the ideal muscle group to hold this tension. Before every shot, I mentally visualize the feeling of no tension in my bow hand, bow arm, bow shoulder, neck, release shoulder, release arm, and release hand. It is a feeling quite like what John described as "hanging there".
To get a good idea of what this should feel like, with nothing in your hands, put your arms in the position of holding a bow at full draw, with yoru head fully straight up, and build tension in your rhomboid muscles in your back, if done properly you can use that tension to hold your form there while being perfectly relaxed in your bow hand, bow arm, bow shoulder, neck, release shoulder, release arm, and release hand. Sometimes when I am shooting bad shots I will actually do this exercise with no bow in my hand just to feel and anchor the feeling of the tension being in the right place.