I didn't even realize that Zentangle was an art form. I thought it was just what you doodled on a pad of paper while talking on the phone. My thanks to talented multimedia artist Cynthia Schelzig for this suggestion.
I felt a little stuck at first because I was actually trying to focus on what to do. The further along the drawing went, the more I let go, and the easier it became. A great loosening up exercise.