The Valve team has released some interesting reading material on character creation.
Jude Jackson writes:
This isn't exactly news, and I'm sure many Blender artists are already involved in the Dota 2 workshop community, but Valve has released some very thoughtful and comprehensive guides to their character design standards. If you read the resources, especially "Dota 2 Character Art Guide", "Dota 2 Character Texture Guide", and "Shader Masks Guide", you can read some helpful notes from the Valve art directors not only on how different real-time shader features work, but you can also get some insight into what sort of thought goes into creating interesting and recognizable characters. None of this is Blender-specific or even references Blender, but any 3D artist should find some value here.