I think your designs are too cluttered with detail. There are no places for our eyes to rest, and since everything is equally important, as a consequence, nothing is important. Sacrifice local detail to enhance the overall expression. I think your images would benefit from you choosing places of interst more carefully. And since you dont need to render everything out, you can be more productive =)
Furthermore, I think you should draw more verbs and adverbs and less subjects. Give your poses meaning.
Finally I think you´d experience a faster development if you´d vary your subject matters more.