One of my favorite things about anime cons is the amount of raw creativity charging up the air. It's not just the official artists. Anime has a very involved fandom, and almost everyone runs a game, or makes their own costumes, or runs a mailing list, or.... so it's almost impossible to NOT get inspired.
It's also near-impossible to make a finished piece while bouncing up and down, dealing with customers (lovely customers! I mean it! They wear such awesome clothes...) so I use the time for brainstorming and trying out new tools.
Yesterday, I did this with a set of watercolor graphite pencils:
The pencils were very easy to use, and required almost no water. The effects I got-- on some frankly awful paper, and with just a few tablespoons of water and one thin brush-- were like ink wash, without the constant danger of emblackening everything on my table.
I'm still working up the picture-- it's a rare one that's worth saving, I think, so I'm trying to save it (for reproduction, not original sale. It really is horrible paper.). So feedback is welcome!