Overall it looks pretty decent but the c4dish things that cover most of the background are either low quality or oversharpened which really bothers me. I think you could also blur some of them to create a sense of depth. It does have some depth I just think that you could emphasize it a little bit more.
Then to talk about the render you picked, I think her hair on the right side looks way to sharp (I guess that isn't something you did, you just picked a weird render, but you can fix it) WHAT COULD BE AWESOME IS BLENDING IT INTO THE C4Ds, because the hair really has a simular style as the c4ds, just thinking out loud here, might actually be very ugly)
I also think that the hand holding the bow is way to blue. I'm guessing there was a second lightsource in the original picture. (YOu can fix that pretty easy though)
The sparky yellowish orange bulbs and dots do not really fit cant really put my finger on it. Seems a bit to random.
But do not be sad hahah, like I said in my first sentence, despite all of that, its a pretty decent signature. You can make some people very happy with this one.
EDIT: Would be cool if you added some purple somewhere in the picture since the render has hints of purple aswell.