I often tell my students that you can't worry about the end of an improv scene because the end is not up to you. You just play as hard as you can until someone changes the scene. The scene has changedthe end is not up to us.

People doing rote assembly-line movements, or someone tossing dough over and over in a pizza parlour is boring. It’s boring to watch and boring to perform. But if you’re a bad pizza thrower who drops the dough or watches it stick to the ceiling, then we know something more about your character.

The same energy used to point out someone's flaws, can be used to work on your own.