I don't peruse Pinterest much these days, but when I couldn't get to sleep last night, I hopped on and found this picture meant for coloring purposes. (Click on the picture to visit the Pinterest link.)
I had a moment of creativity. What if my artists could draw something similar. I figured we could make it a lesson about lines, shapes, and patterns, which sounds fairly artistic to me. By the way, I never showed them the picture above. Here's what they come up with.