Low quality and not blended. Change the C4D layer to "Lighten". Smudge a bit. And find a better quality render. (Btw, save as .PNG)
You should search some tuts on DeviantArt. A lot of them are basic and can really help you on your blending.
also, i save as png...but it still loses quality...what should i be doing besides that? because alot of the siggys ive made look really nice in photoshop, but don't look so great here...