Vi Hart’s site is fabulous. I keep banging on to my students that it’s not just OK but important to doodle in maths. It helps you ‘see’ problems if nothing else. Some get it, some think it’s just a bit weird. Then I show them videos like this.

Vi, despite the manic voiceovers, shows that maths can be explored with doodling. In fact, doodling helps you make mathematical discoveries. It gets the students hooked. Do have a look at her page: Vi Hart: Math Doodling