More videos/info: http://vihart.com/doodling
Doodling Snakes + Graphs: http://www.youtube.com/watch?v=heKK95DAKms
Doodling Stars: http://www.youtube.com/watch?v=CfJzrmS9UfY
Doodling Binary Trees: http://www.youtube.com/watch?v=e4MSN6IImpI
http://vihart.com