Do you ever miss-hit easy/slow balls? Notice how, many times, you miss hit a ball that you were about to hit into the open court for a winner. Do you know why? The answer is, you were probably glancing where you wanted to hit the ball and didn’t track it all the way to your racket.
To remedy this problem just focus on the ball from your opponent’s strings all the way to your racket. Try to read the letters on the ball as it is coming toward you.
Condition yourself to track the ball all the way to your strings and you’ll hit many more winners than errors.