Typically, I won't do any thumbnail sketches in preparation for a full-sized cartoon. But yesterday, I wanted to be sure of the positioning of the figures within the composition, so I did a few. As you can see, by studying the one I decided to go with, it didn't change very much from the original thumbnail. Once I have a picture in my mind as to how I want the elements arranged within the picture plane, I usually don't stray from it too much. Thumbnailing is a great way to weed out all of the bad decisions you don't want to be making as you ink.