"Keeping my control fine-tuned," Luke said, raising a hand; the duffel bag he'd brought with him floated over, and he reached in and pulled out a couple smallish rubber balls, like the kind the students in his class used on the playground. He placed one on the ground in front of them. "Just because I'm a Jedi Master doesn't mean I shouldn't keep up my practice. Everyone should, no matter how strong they are with their particular talents."

As he spoke, his hand shifted, using the Force to lift the other ball and balance it precisely on top of the first.