Grab a pen, a few sheets of paper and cue up this TED Talk. The presenter takes you through some cartoon drawings which require just a few strokes of the pen. It's along the same lines as Ed Emberely, where you appreciate that just a few well positioned lines is all it takes to make an object or person come to life.
Lately, I've been keeping my TODO list on index cards and rather than tossing them, I've been sketching on the back. Hardly great art, but it sure is fun: