I really love some of the stuff you're doing with colour, though you could probably try to vary your saturation more. That latest face is gorgeous... only thing I can point out is that his ear looks a bit small.
i really like the sargent studies too... something i've been thinking about lately: whilst copying or drawing from life, learn to emphasise things which may or may not be there, to make the picture more comprehensible and or work better
Well, it's a lot about experimentation with me. Just throwing colors around, loosely following color theory, and seeing what sticks. Doing a lot of oversaturating the shit out of the piece, and softly blending neat looking areas to the original painting.
Sorry, it's a bit difficult for me to make it into words, as I never really think about it!
I love the ram human thats grumpy over his cheese. And the bear. And everything else =) You Have a firm grasp on colours!! You seem to enjoy painting with digital mediums like you would with oil, right? I like how in the bear you use photoshop textures that are hard or impossible to get with oil. Good work