Flowing Line Exercises

When I was bored as a child I would play around with lines on a paper. All kinds of swirly flowing stuff. And then turn these lines into all kinds of things:

Fruit and flower vines, smoke coming out of genie bottles, dancing ribbons, clouds, snakes, dragons and any fantasy creature you can come up with that bends and twists... the swim and flight patterns/paths of birds, insects and fish swarms.... the ride of roller-coasters.

You can create incredible dynamics with what you already know.