In 2009 I worked as the board artist, background artist, and an animator on Sonic Bunny's "An Okay Place to Eat" pilot. It was a lot of work, especially since it was all on the side (I was fully employed at a studio). But, it was worth it.
I volunteered to create the backgrounds for a friend's share of another friend's pet project he was doing for a friend of his own. So, I the first friend in the previously mentioned chain of comrades gave me two sheets of thumbnails, 21 in all, as well as two backgrounds she had created before I opted to take over. I modeled the first two backgrounds I created on hers so I could get the style right (although it was right up my alley anyway).