With these ATCs, I was the first player - I made the background and sent them off to others to work on. When you are the first person, it's less likely you'll have any idea how the cards are going to come back, though of course, you hope they sort of follow your theme, if there is one. This card had little theme beyond blue and brown - it was made from part of a chocolate bar wrapper and some washi tape.
This car had a little more theme to it; I used a poem text for the background and put a charm on. But still, lots of room to decide which direction to take it in!