I've had three designs complete scoring now, and they've all received fairly low scores. The general consensus about my work seems to be that I have good ideas, but my style is too simple. I guess I need to learn how to do detailed line work. I don't have a copy of Illustrator, only Photoshop, but as I understand it, these vector-y sorts of graphics are easier to do in the former than the latter. I'll figure something out.

My designs: