Your first image is pretty basic, yet it's simple and elegant, which I like.
Your second image looks like it's just a render added with brushing in the background. I'd say try to blend more and work with different brushes and C4D's.
The first signature is really sweet and simple. One thing you might want to be careful about is text used for skype names. Its usually better to make it as clear as possible just to be on the safe side.
