I think anatomy and jagged outlines should be your current concern. Respective to the artworks in the order you posted them.
Also, contrast and saturation can be your friends. even I have trouble with those two things myself. Try messing around with the shades and see if you can get a more brighter light shade on the second one and see what I mean.
Also, contrast and saturation can be your friends. even I have trouble with those two things myself. Try messing around with the shades and see if you can get a more brighter light shade on the second one and see what I mean.