Practicing your process improves your performance. Your process is your routine. It is what you do in order to make a putt.
For example, I strongly believe in using an intermediate spot about 6 inches in front of the ball. The intermediate spot should be on the target line. It is a spot that if your ball rolls over it with the proper speed, the ball should roll in to the center of the hole. Your focus should be on rolling the ball over the intermediate spot not on making the putt. Let me say that again. Your focus should be on rolling the ball over the intermediate spot not on making the putt.
If your putting thought is focused on making the putt instead of the process you will see less success in the results. Most tour players will tell you they aren’t thinking of anything as they make their putt stroke.
Practice your process on the practice green so you will stop evaluating your stroke based upon whether or not the ball goes in the hole.