It has a few (yet important) issues:
1) It has no depth: the render and the background seem to be flattened up
2) There is no focal point: You don't know where to rest your eyes on,as everything is a sparkle/filter
How to fix:
1) Make the render bigger,with less filters on the focal point (especially the face,i'd like to see how her mouth is LOL) and "play with the render",meaning,make something to make the render "interact" with the backdround,a silly example would be a swirl,it'd already give some depth.
2) Less C4Ds,if a C4D is just as big as the subject,then you're doing it wrong,also,avoid using those sparkles and using the light effect on top of everything: the first looks terrible in almost any occasion and the second flattens the image completely.
3) Be more creative with the text,really :x
*edit*
For a such kind of render (which i found interesting to work with :3) i'd go for something like this:
Link of original size image (as the top one is resized):
https://oi43.tinypic.com/10893qt.jpg
If you wish,i can "lend" you the .xcf for learning purposes btw