Build in creativity time. For me, it's connecting with creative people. Or sitting in a coffee shop, of all places, and, with a legal pad and the Bible, just writing. Or sometimes it's driving in my truck and listening to DC Talk or Audio Adrenaline. These activities seem to unlock creative thoughts.
Creativity often happens away from the office.
When you change your usual environment and get a different perspective, creative thoughts have fresh, fertile soil in which to grow. But we write down every thought and hammer it out. That's why I never have our staff meetings on the same day or at the same time. Sometimes we'll go fishing with cane poles and that will be our staff meeting. Another staff meeting might be tie-dying a bunch of shirts.