What about journaling?

When you get out of a manic episode, write down EVERYTHING you regret doing, and I mean EVERYTHING. Also write down how you felt as a result of these actions. It will hurt to write all of that, sure, but you can reference this journal entry in the future when you're manic. e.g., "I want to buy $500 worth of electronics!!! Oh wait. I did that before and look what that did to me. Then I felt depressed that I messed up."