Passion? Check

I won't bury the lead. If you ever want to be good at improv, you need to be passionate onstage.

Read improv literature? Fine.
Listen to teachers? Fine.
Study shows? Fine.

Passion offstage is helpful, but if it makes you a chemist onstage, attempting to formulate the best scene, stop. Stop reading, stop listening, and stop studying improv. Instead, think about why you want to do improv. Do it because you love improv, and you'll be captivating onstage.

I was recently at a local restaurant, and noticed a girl just a few years old. She was mesmerizing, and while I didn't want to concern the parents, I couldn't help but watch her. Written through her actions was joy. She was intense, and committed to her emotions, because she was happy to have them. Even when she moped, her frown said, “I will do this, and I’m glad I can.” She was energy, joy, and passion. She loved living, and that was entertaining.

Love improvising, while improvising; the audience will notice and appreciate. You’re there to give to the scene. So, do it, completely.