If you haven't yet begun tracking picture book ideas, now's the time. Whether you use your phone, a notebook, or the back of your hand, write it down! Don't assume you'll remember it later.
Train yourself to tune all of your senses in to picture book possibilities. Who knows? Your next picture book might originate in an overheard comment, a memory triggered by the smell of bubblegum ice cream, or the feel of your cat's tongue licking your hand.