Ohai!=D
1. BG of one c4d looks odd, try smudging it.
2. Text is a generic black font. Try something smaller, under the sword, and in a cooler font.
3. Yellow render + red BG = :puke: , try to create an atmosphere. Whether it be a city, smoke, fire, water, sky, space....etc etc
4. Sometimes it's almost best to create an amazing BG then try your best to get the render to fit in.
5. Smoke over the render takes away from the focal.
6. Lacks depth: I see around 5 layers, and none well blended. Try adding more infront of the render toward the bottom.
7. A thicker border would better suit this tag.
Keep up the work, practice makes perfect.

---------- Post added at 07:43 PM ---------- Previous post was at 07:41 PM ----------
Originally posted by DeCiMaTi0N
If you like the work (I believe all the GFX pros will back me up on this one) you should just thank the post rather than comment on it which does the creator no good whatsoever. Coming in here and telling people there sigs are "awesome" just because they can do better than you is not helping them out. I understand you have an opinion and I respect it, but I am sick and tired of the bullshit in GFX with random people coming in with no experience in GFX and giving people false hope. I have seen some god awful sigs that noobs have came in and said were "amazing," and am frankly sick of it. Feel free to give me -rep for my opinion, frankly I do not care. (BTW groans have been set to neutral rep so I didn't hurt you by groaning your post. So if your mad about that than you can calm down.)
@people who are here to give real CnC: Sorry for the rant
You have learned well, young padawon.
*bows*
Voice your mind and help improve others.