These were my rules I pulled together for the Washington Post:
1. Cut your losers short, and let your winners run.
2. Avoid predictions and forecasts
3. Understand crowd behavior.
4. Think like a contrarian (but don’t always act like a contrarian).
5. Asset allocation is crucial.
6. Decide if you are an active or passive investor.
7. Understand your own psychological make up.
8. Admit when you are wrong.
9. Understand the cycles of the financial world.
10. Be intellectually curious.
11. Reduce investing friction.
12. There is no free lunch.