Anyway, looking at a lot of your signatures I have these problems with them:
1. Effects over the faces...big no no. At least in my opinion. It just really kills the focus of the entire composition.
2. The tags are a bit too tall for my tastes. As a personal preference, I like my signatures/tags looking more like a rectangle than a square.
3. Colors: try using more vibrant or interesting color combinations.
I'm interested in seeing what else you'll make. Keep it up.