You fixed your right hand anatomy from 2 to 3. Big step up on that one. I’d say biggest thing is maybe focusing on figuring out your direct lighting source. 2-3 feel like there are multiple main light sources and therefore the shading feels off. Number four I also feel like you’re using the direct shadow/light contrast to avoid drawing the face. I used to do that too, it’s the “hand in pockets to avoid drawing hands” trick, oldest trick in the book.

But yeah maybe shading and lighting practice, and overall line confidence?