An extremely important part of your game is the pre-shot routine. A great pre-shot routine will make your shot execution more consistent.
Before you get down on your shot, walk around the table and look at it from all angles. Decide exactly what you are going to do, exactly where the cue ball is going, and locate the exact aim line. Do all of this before getting down on the shot. Once you are ready to lean over and shoot, the only thing you should be doing is executing exactly what you have already decided to do. Your focus should be on the object ball as as you pull the trigger.
Never think about what to do when you are down on the shot. Don’t change your mind, move your stance, think about position, etc. If you do, stand up and start over.
Doing this will help form mental toughness. Your shot making will become more consistent.