Just as St. Croix said, most of the time it's a footwork thing where I've gotten sloppy over time. I just try to free everything up and trust in myself.
Slumps can hang on longer than necessary when we worry about them and overwork ourselves trying to get out of them. If we decide that a slump is a period of time when we merely don't score well it can become a monster.
What am I getting at? Scores, good or bad, can be deceiving because they are only part of the picture. However, if I'm struggling to hit a target then it's probably something I should correct.
Think of all the nights you didn't execute well, and yet scored well, and vise versa. Realize that if you're executing well, and repeating shots with some regularity, the scores will usually take care of themselves before long. Take a step back and trust in your abilities. Don't allow your self esteem to be based solely upon scores.