A trick I learned in the Marine Corps was not just to think about squeezing the trigger, but to actually wisper "squeeze" outloud as you squeeze the trigger. But draw it out over a longer time and focus on making your finger squeeze the trigger as slowly and steadily as you say the word. The result is usually that you are concentrating enough on squeezing that the shot surprizes you, which is your goal. It should go like this if you do it right "(inhale).....(exhale)....'squeeeeeeeeBOOM!'" If every shot surprises you then you won't have time to flinch or jerk the shot off target because you didn't anticipate the shot. After you do it a few dozen times it starts to become "muscle memory" to always squeeze that slowly and steadilty and you will find that you don't have to actually say it anymore.

I know it sounds silly, but it really worked for me. When I went to the rifle range (having shot all my life and developed a lot of bad habits, I might add), I had a real problem with rushing and jerking the trigger. I still use this technique when I shoot hard kicking guns to beat the flinchs. Another thing you can do is to take a deep cleansing breath before you look through your scope and remind yourself that the recoil won't hurt you. If you are calm and relaxed you'll shoot better, and the effects of recoil will be lessened.

Mike