Here are a couple of round robin card sets where I made the backgrounds and sent them along. This first one is kind of a cheat, because the background came from an old piece of art from Sarah's GCSE art folder - I cut it into pieces and added some tape, but I just thought it would make an excellent background - and I was clearly right.
I do like sending very general backgrounds out, just to see what they inspire other people to do!
Of course, sometimes it's fun to send a more specific background out - this bird obviously provided a lot more direction than the background above. I like how the two others who worked on this card left quite a lot of open space on it - it suits the bird, I think.