For all of the pieces I've seen, you have really good base colors. But the material rendering isn't quite there. Don't get me wrong, there's great improvement since you first started. Doing some studies from realistic lighting references would help you a lot when transferring the study to the hand painted look. Keep at it.…
Gonna have to add some more shadows to them. Also need to make them kind of shinier and more reflective but don't really know how. Pro tip: Surface, light, and render your model normally (i.e., using shaders for metal/flesh/whatever surfaces) and use the render as a basis for painting your maps. (Or, to put it another way:…