flonnebonne | Art commissions for charity?

Since I've been drawing a lot lately, I've been thinking of taking art commissions for charity on a casual basis.

I.e. someone says "draw x" and when I have time I draw it, send it to them, they get to decide how much they think it's worth, and they send an according amount of money to a charity of their (or my?) choice. It would all be done on an honour system because honestly, my art is not that great and I don't think people would lie to get it. Also am too lazy to set up anything more strict when I don't think I'll get many requests anyway. XD

Was thinking of doing the actual requests on Dreamwidth because it's easier than Tumblr to track things. I still don't really understand Tumblr, although that's where I usually post art. Also, would probably get fewer requests on Dreamwidth, and that's kind of what I want. This is just supposed to get a little social good out of a hobby I do anyway, not make it into a big time-eating project.

Any advice from anyone about this? I googled a bit to see if there are any groups that already do this that I could just join, and there are some, but I didn't see anything that looked really established and on-going. If anyone knows any, let me know!