This tutorial comes from http://thepunchlineismachismo.com. It is PACKED with excellent information. Whatever your problem drawing area is, it's sure to have something for you.
If it doesn't blow your mind, I'm not sure what will. Be sure to check out http://thepunchlineismachismo.com and see the great comic that all this knowledge has produced!
For more great tutorials like this, visit http://thepunchlineismachismo.com/archives/553
Thanks for this.