Secret #1 is the biggest one: More bad ideas. The more bad ideas the better. If you work really hard on coming up with bad ideas, sooner or later, some good ideas are going to slip through. This is much easier than the opposite approach.
Secret #2 is more important: Generosity. It's much easier and more effective to come up with good ideas for someone else. Much easier to bring a posture of insight and care on behalf of someone else. It lets you off the hook, too.