First of all remove that border, it just does not fit to the signature. So let us see. The contrast on the render is very high, I would maybe make it at 60% less since the shadow comes out very hard and it is hard to concentrate on details as the eyes and things like that. On top of that the left side appears like this very dark, considering the weak light source from the upper right (which could be improved a little too) it is really too much. Let us move on a little. What is the ugliest (sorry) about that tag is the brushing at the hair. It just looks random, without any flow, without any reason, just put there too have an effect so that the tag itself does not look so empty. The color of the background is a little messy as well. It goes too fast from the nice red to the blue. You have to keep the red a little further around the render so that it is more in the focal. The flow on the right side is there, not complaining about that one. :> But it is kinda weak. You could add soem by smudging if you really like to smudge or just adding some more c4d renders or something. I would consider to add a text at the black part maybe, or even very small in white and arial on soft light somewhere where it does not steal our attention. keep it up.
Oh wow, I made this sig on my laptop and it looked good....now im on my desktop and the contrast is mega high and the smudging looks like ----.
Haha. Those might be the settings you put on the screen on your laptop. Me for example is working with 0% light. In the last step I always have to turn it high to around 60% so I know how you gusy see my signature. Before I noticed that the comments were like: I though, my eyes, omg this is bright. Or something like that. :> Just look up the settings or just work on your computer. :] Keep it up.