It's been a really interesting process. It immediately pointed up certain problems with the plan as I had it, mostly because, as with picture books, you have to be very aware of how your material works as spreads and of course can't have random single pages. So, I have been re-jigging things, nipping and tucking my content. I did a rough flat plan with coloured pencils first then, once it was working properly, did a posh version in Photoshop:
I'm excited to meet my editor and keen to get started! I'll let you know how it goes.