I often enjoy re-reading many of the astute observations in the Psycho-Cybernetics classic by Dr Maxwell Maltz.

To recap, here's one of them: 

"To accelerate your determination to get more out of life, you must learn to use your great creative mechanism as a success mechanism, not as a failure mechanism.

You must develop new ways of thinking and imaging so that you will build a strong, reality-oriented self-image, which will give nourishment to your success mechanism, leading the way to happiness."