I have always been inspired by the weird color combinations that happen on the paper scraps I use to mix paint; somewhere there's a box of the best ones. Recently I decided to start mixing colors in a small bound book, so they'll all be in one place.
A while back I wrote a book about collective nouns with a Halloween theme ("A Rattle of Bones", Orchard Books 1999); I've always wanted to do more along that line, so I've been playing around with a list of baby animal names. This is a scribblier style than I usually work in, but the loose colors in the mix book demand it. My usual styles are so fiddly that it's nice to be forced to be a little looser.