Jr111. You keep mentioning “trigger finger”.
Here are the two most important tips, in this regard (imo).
1). Focus! By this I mean Eyes ON The Front Sight. Literally! (Keep the target in the blurry peripheral background).
2). “Let IT surprise you.” By this I mean, when/as you squeeze trigger, move nothing nothin nothing but the trigger finger. Nothing else moves. Eventually, at a point , somewhat, unknown to you, something will go bang. Let that bang be a surprise.
If you follow the above, you will not miss.