I recommend regular practice with the Best Me Technique (Gibbons & Lynn, 2010) in self hypnosis as a way of involve your whole person in visualizing successful performance, so that you can experience now, in the present and in concentrated form, the rewards and satisfactions which would not normally be yours until success has actually been achieved. This will not only improve your performance, but it will also provide you with the motivation to pursue it.
Each element of the Best Me Technique corresponds with a dimension of experience (Beliefs, Emotions, Sensations and physical perceptions, Thoughts and images, Motives, and Expectations), which may be used in any order and varied and repeated as often as desired in order to involve the imagination as completely as possible. I'm going to use bowling as an example of how to use the Best Me Technique to improve bowling performance, but it can just as easily be applied to other sports such as baseball, golf, and soccer. Here's how it works.
First, find a quiet place where you are not likely to be disturbed. Close your eyes, and after inducing self hypnosis as described in the link above, imagine or picture yourself about to bowl a successful strike, using imagery like this:
Beliefs. Believe, or picture in your mind, that you are headed towards a certain and inevitable success.
Emotions. Feel the thrill of achievement surging through you as you realize that victory is assured.
Sensations and Physical perceptions. Listen to the sound of the ball rolling down the chute while the people around you grow quiet.
Thoughts and Images: See the ball hit the pins directly, and watch them go flying in every direction .
Motives. Realize that this is how you want your bowling to become.
Expectations. Allow yourself to fully savor in your mind the fruits of your success!
Believe it will happen, expect it to happen, feel it happening, and savor in advance the fruits of your success. Practice and rehearse regularly, and with patience. And, above all, make sure that you enjoy it!
Gibbons, D. E., & Lynn, S. J. (2010). Hypnotic inductions: A primer. in S. J. Lynn, J. W. Rhue, & I. Kirsch (Eds.) Handbook of clinical hypnosis, 2nd ed. Washington, DC: American Psychological Association, pp. 267-291.