Preparation
Doing some sort of research to gain knowledge of what needs to be accomplished
Concentration
Organizing one's thoughts and focusing on finding or creating a solution
Incubation
Allowing your subconscious to work on your ideas while you perform everyday tasks
Illumination
When your ideas come together and a solution is found or created (the "aha" moment)
Verification
Reexamining the process to make sure that your solution is valid