I really believe that the way you percieve your world affects the way it percieves you. In other words, if you think things will go your way they generally will. The trick is to really believe. Steve Pavlina has an interesting article on his blog that talks about turning negative thoughts into positive ones.

He uses an image morphing method -- basically turn the negative thought into a silly, bright, animated image that represents the negative thought. Secondly create an image (similarly silly, bright and animated) that represents a positive thought. Finally morph the negative image into the positive one. Below is a link to Steve's orginal article. Theres other interesting stuff there if you are into this.

http://www.stevepavlina.com/blog/2006/04/how-to-squash-negative-thought-patterns/