Hey, welcome back to the forums! This is looking pretty nice!
One thing I'd like to mention though, and I could be wrong here, but it looks to me like you used some sort of glow layer to add lighting on the study. Using different kinds of layers and effects on an artwork is always welcome, but when doing studies, I personally recommend only the basic brushes with nothing fancy on top. Training your eyes that way will be a lot more useful later down the line.
But either way, it's just what I think will help most so feel free to disregard what I say!