Hey bud, you got good colors on the pink and orange one but you should blend the edges of the renders in a bit better. This last one the colors are off and the render is really dark. When you get time you should do this tutorial.
It truely is a wonder you dont have gender identity issues. xP
Arrancar, i like the direction you are heading, however the last signature is definitely not your best. The colors just arent working at all. Try picking colors from the render. Also try to keep the text close to the render. =)
On this one, remember your rule-of-thirds. Also, try to avoid putting text on the focal. You want it close, but not on top of. Excellent improvement. =)
rule of thirds. Imagine a grid with 2 vertical lines and two horizontal lines making 9 boxes in your canvas. The important aspects of your design, such as the focal and text, should be placed either along these lines, or at an intersection of lines. Basically. =)