Halo Wars

v2

The C4D's are grabbing my attention to much. I see two focal points, and neither of them are master chief. Your lighting is decent, creating sufficient depth for the tag.
I'm not quite sure whats going on in the left hand side.
Here's what I would do:
Lose the border first of all, doesn't work here.
Find some good effect C4D's and use your blending options, play around a little bit.
If It were me, I would have used smudging to create my flow instead of slapping on some C4D's going in the same direction, not tryin' to hate on you or anything, it's just what I would have done.
Also, think about tryin' on some photo filters or gradient maps and then use your blending options on them.
Just make a new layer, apply image, then copy that layer ( I believe it's CTRL+J ) and then use that new layer to apply your gradient maps/photo filters to and find a good blending option to use them on. Me personally, I like to use 'color' and lower the opacity to 20%-40% depending on the tag or piece I'm doing.

edit: Also on the color, try to pick colors that will blend more together. If your C4D's are the only parts of the tag that are different colors, then that's where users attention will be focused as opposed to your render.
I felt like giving a half way decent bit of criticism for once. Hope I helped.