I've been doing a whole series of original manga characters, with an obvious dual-theme: colors and costumes. It's taking about 8 hours per character, and the full-size is just massive, so I'm looking forward to making an ensemble poster when I'm through. They're already starting to show up individually as designs on my Cafe Press storefront, Halley Designs. Buy a shirt to wear to the anime convention, if you're not going to actually cosplay with the rest of the crowd.