I personally start copies by copying gesture, then "rebuilding" the character from observation, by using simple geometric shapes (boxes, balls, pyramids) followed by adding detail.
My goal is usually to try to understand how the character works in a "3D" mental space, and as I add the details I keep a close eye in the reference to try to match it and to appreciate the finer details like how clothes wrap, specific features and so on.
I usually end up a bit off in proportions and need to adjust (or just leave it as it is xD), but this way I get a good feeling for the character as a whole and not just how it looks in the art piece.
Still, your work looks really good. We are usually our worst critics, so I'd say keep trying different things and see what you are more comfortable with.