[GD] Trying Something New

I have decided to try my hand at some graphic designing stuff. I have done a little already, such as learning to render and such. I even made my own signature. But this is not about my signatures. This is about things I am learning to do with GIMP and things I design.

So, here are a few things I have made so far. An avatar and a picture of me, both rendered and using transparency. I also have a transparent button that I just made.

Critisism please. Tell me what you think I need to or could do to make them better.