Hey russ, these are pretty cool. One thing I am noticing about your drawings is that you are not drawing through. I can see that arms and costume elements are not connecting to the torso or the other side of the body. Make sure you draw a good structural drawing first so that everything lines up before doing your final pass. I did some quick sketches to show you what I mean, hope it helps :)

Halo from young justice, dc comicy

A couple dc character pencil drawings, one of poison ivy, the other is pied piper, no study of anyone in particular, just references here and there and imagination and splooshing it on the page