I added the horns today, and changed some of the "cloudy" shading on the body to more "stepped" shading, (where colours go in steps from light to dark rather than gradients hitting every shade in between), because I think it matches the shading I did on the face, which I prefer.
Colours are coming along a little better. I found that this orange-ish background works pretty well to make the bird stand out all over (body stands out 'cos it's dark, head stands out 'cos it's an opposite hue - gogo complementary contrasts), although I might just try cycling the whole image hue round to see if I like an alternative pairing. It occured to me that the bird's body could be a light colour (even off-white or something) but with a dark grey or black head, maybe to indicate that the face on the bird is only a stone mask? Maybe the guy could be a sort of opposite colour, with a black coat and a head the same colour as the bird's plumage? I ought to sketch some of these out on the computer.
I did some exploring through the photoshop brushes and there's a ton of them at the bottom that are actually supposed to recreate genuine real-life brushstroke styles. I always avoided them, because they seem sort of fake-looking sometimes, but here they make the sky look a lot better than my previous attempts. Also, I changed the messed-up shading on the nose.
I'm still uploading PNGs without the "rider" layer on them because I still can't decide how to pose him on top of the bird. ;_;