Your graphics aren't half-bad, but there's always room for improvement. I'd like to know, do you use GIMP or Photoshop? Also, though I can see you have a sense of consistency, I wish you could make it seem as if the render's apart of the background-ish. Not to be rude by any definition of the word, but the render seems to just sit on top of the background. Additionally, there seems to be a lot of extra space in your backgrounds. What I recommend is downloading an assortment of free brushes (you can get some off of dA) as well as free C4D renders (also from dA). With different brush patterns, you can smudge images differently, or create a more diverse pattern on your images. With C4D's you can add a bunch of cool effects to your image by putting the C4D on certain modes (i.e. overlay, lighten only, addition, etc). If needed, there are tutorials on how to use C4D's (you can probably find some on dA).