Self-titled designtrepreneur Joe Gebbia has a pretty simple process for finding happiness in three steps.
Here's the idea:
Step 1: Identify one thing you do that makes you unhappy. Write it down.
Step 2: Look at what you wrote down. Replace it with something that makes you happy.
Step 3: Repeat one week from now.
For another perspective, learn why experiences matter more than possessions.
The Happiness Process [Joe Gebbia's posterous]