Flash Frame-By-Frame Animation: Detailed Animation Part III
From Adrien-Luc Sanders, former About.com Guide
When you’re done, you should have the basis for your cleanly outlined shape, though it may not look as clean as this (I did this quickly, but I have a lot of practice). You can see that I’ve still got a few problem areas, though, where the curves don’t join properly or invert from how I intended.