I have been overcutting any shot to the left. I have bought some paper a$%holes so I can just go in to the pool hall, set up the shot and repeat the same shot. If they are sensitive about the technique, I use the condensation off my soda to mark the table. I have seen people use spit, but really feel the acid in saliva are bad for the table and I don't want my dna embedded into the table. Then I shoot the shot 15 times. I keep count of the number of times I am successful. If I am missing, I move in. I want success. Once I am hitting it, I move back. Pool is not an overnight learning curve, but over several months I have gotten better. Good luck. Also using a straight line of 4 balls and shooting different cue ball positions is helping me understand different english effects. I do best with a center ball hit. id I attempt any english I reduce my chances, but sometimes if I can't make the next shot with out trying english, I go for it. Experience is the end result of practice and playing. John
PS If I am not invested in the game I get sloppy also. I think it is referred to as "playing down to their level"
I played in a tournament and knocked out some fairly good players, then lost to guy that I did not take serious enough, left him on the 9 after running 4 or 5 balls. Sucked, but the truth is I f%^&ked off and lost.