I have been experimenting with a form of doodling called tangle patterns. It is very much like what i have done in the past but now I have access to many designs to add variety. I like how one is taught to lay out a grid or a string line to boundary the drawing and keep one from bloating the drawing out of proportion. The lessons in shapes and shading have taught me a lot about drawing.
I was experimenting with a wavy line and came up with this idea that I think is unique. Couldn't find another like it with google.
Try it. It's fun.