If you’re writing picture books, you’ve certainly heard these words more than once.
Leave Room for the Illustrator.
One of the most important aspects of  illustrations is how much information the reader gets from the artwork that is not narrated in the text of the story. Picture book readers trust that the illustrations tell the story as much as the text, and often times more than the text. Illustrations convey emotion, definition, story arc, plot twist, and surprise elements.
In studying picture books which do this well, it’s helpful to practice writing  your own art notes where you think it’s important to the story that the illustrations depict a specific element. I sometimes mark the page with a post-it note to show where I might have added a note if I were the author. Then look back over these notes and try to word them so that my meaning is clear without interfering with the illustrator’s work. Later I can rewrite these in a notebook or just stick the post-it note in my writing journal.
Shutta Crum must be an expert art note writer. Her books Mine! and Uh-Oh! are written using only one word each! If not, how were these nearly wordless picture books written since she is not also the illustrator? Although I have heard that some writers write in a side-by-side column, with the text on one side and the art note on the other, I cannot say with certainty that this is how Shutta submits her work. But it is a good exercise for us to practice.
Look at these spreads and think about what is necessary to put in an art note and what can be left to the illustrator’s imagination.
Notice that it isn’t always important to leave a note. Do the children need to be siblings or friends? No. Is the specific collection of toys important? No. Is it important that one toy get left behind? Yes. Is it important that there is a dog in the scene? Yes. (That comes out later int he story.)
Note: There are more of these than you realize.
I wonder how many, and what kind of art notes Tammi Sauer included in her first manuscript for Your Alien. I’m thinking there weren’t as many notes as in the example above, simply because there is more text in the story. The illustrator is an adult who can visualize a scene without help.
Take a look at this scene. Was it necessary to say exactly what the alien should be eating (or even doing) on this page?
I don’t think so. The alien could be eating popcorn, bananas, or pizza. He could even be zipping around the room or playing with the cat instead of eating. Either way, it doesn’t affect the outcome of the story. This is purely up to the illustrator to decide what ‘other ideas’ the alien has on this page.
Even books which are written and illustrated by the same person, must have a certain element of art notes even if they are not specifically written out since the work is submitted as a whole unit, not in pieces.
My guess is that Chris Haughton either jotted down ideas in words or sketches before he produced the final art for his story, Shh! We Have a Plan.
Before he began illustrating, he knew that the littlest character was a different kind of hunter than the others. He was kind and friendly. He was always the first to spot a bird and instinctively attracted the birds to himself. He didn’t carry a net or a ladder, but used bread crumbs to charm the birds.
As a writer of picture books, balance is the key. Tell your story in a way which allows your reader to be an active participant. Give enough information to feed their imagination while allowing them to make their own connections.