Need help! Shading and texture, clusters; don't know where to go from here

[LordCleveland]

Attached is the image I'm working on.

I've decided for the most part how the light should hit the image, but I'm really struggling with how to apply this to a robe.  I want him wearing your standard wizard robes but I can't really visualize how that is going to look.

Could really use some insight!

[LordCleveland]

Updated, tried some of the cloth myself

[CFKaligula]

edit:


An important part of picking colours you forgot is Hue-shifting, this makes especially the cloth look very bland. For clusters, try to make them as blocky as possible. You can see I tried adding a nose to his face as well, just to give him a bit more detail.