I love these smaller books because I get to explore and try different things. We usually only spend a week or two on them, so they're simplified quite a bit.
Experimenting with new brushes in Photoshop; New textures; different way of drawing trees and environments.
I don't like apes/ monkeys btw. 'Planet of the Apes' disturbes me to no end! I hate those movies! These little monkeys may be cute here, but all the preliminary sketches were horrific little monsters! Gorillas are cool though. :-)