This is really lovely! Just about your process- you obviously start with the tonal values, but after that do you stick another layer on top (like a colour/overlay layer?) and then make other layers when you add some extra detail? I'm just interested in your technique because it looks really good!
The order of my work is as follows: - Tonalny image - About what will define the color - Then two layers of shadow and light - On top of the layer on which a small brush work through small details: glare, relief, hair and so on. I have a lot of layers, but it is always possible to adjust the image. I hope that I was able to clearly explain)
Your finished product is gorgeous. You're an amazing artist. I'm a little confused by this though cause looking across his chest and left arm and such it seems like the darker parts in the second picture become the highlights in the third.