I agree with darthmongoose about the backgrounds.
From me, the anatomy on the characters still needs more polish. Like I can notice that you often tend to avoid drawing hands and its understandable, I've been there before, but you won't be able to draw them ever if you don't try to draw them more often. In your level, I suggest you practice more on breaking down the anatomy to simple 3d shapes like how arms, can be drawn as two cylinders connected by a sphere. That way you'll learn to give more structure to your character's anatomy.
Also, if there are poses you find difficult to draw, then you can't go wrong with using photo references. Many artist underestimate the use of references, but I can't stress it enough how important it is to use them. After all we can't draw everything from imagination if we haven't seen it before.
Lastly, seeing as you prefer to draw in the typical manga/anime style, I recommend watching some tutorials from DoKiDoKi Drawing on youtube. They give some pretty good advise for those who wish to draw anime-like style in general.