Surprise!
Be surprised by yourself.
First do, then think. Or, as said before: first jump off the cliff, then figure out how the parachute works. That's precisely what you have to do to keep on inspiring yourself or, in fixed groups, your partners.Going boldly where you have never gone before is always rewarded in improv. Embrace the unknown, go to where the danger is and... surprise yourself. It's fun! :-)