Black Lagoon is my favorite anime series, so it's always nice to see a wallpaper of it. However, it also makes me more critical because my fav. series has to be represented well of course!
The good news is, I think this wall does fit in the whole BL theme. To be honest, I don't see this as a very good wall though, but it's your first time, so you got a road ahead ;). This is a nice start.
My main points of critique are the poor scan recovery and the very simple use of the eraser tool and brushes for the ashes and scratches.

Well, good luck with your future projects and be sure to run them through Section Zero first!