I definitely shoot better when I am relaxed. Grip is also important. The key, I believe, is isolating the trigger finger. I use my other three fingers to pull the butt back into my shoulder, moderate pressure. My thumb lies limply on top or slightly over centre. Works best for me anyhow.I would go back to the post where the guys recommended watching the grip on your firing hand. Movement induced by squeezing the hand to pull the trigger is one of the biggest buggers I have seen repeatedly. When My 4 position indoor match rifle scores go to hell that is invariable the culprit. Comes from trying to hard.