It's pretty good for your second sculpt. Have you sculpted over an existing miniature (I'm looking at the feet) rather than use and I assume there's an armature?
As for ways too improve: the easiest is to compare yourself to other sculptors and how they sculpt. Not so easy back in the day if you did not know anyone, but with YouTube it's easy. I did a quick search and Tom Mason's series seems like a good place to start. Copy what he does, and see how close you can get to what he is doing. Post the results back here.