Picture Book Dummy

I've been illustrating for a while now, but I've long wanted to both illustrate and write my very own picture book. I had jotted down a simple story a couple years ago, poking at it now and then whenever I had some spare time. Pulling it back out this summer, it seemed ready for the next stages - layout and sketches. This drawing will be the spread for pages 4-5:All the sketches for the book are nearly complete with only minor adjustments yet to be made. Oh - and I still have the cover left to design. I always leave the cover for last when illustrating a book so as to maximize the amount of time I have to ruminate on it. Once the sketches are complete, I'll need to paint two or three finished illustrations before it will be ready to submit to publishers. I'm contemplating dabbling in media different from my usual for this project - possibly digital or perhaps try out some the textured gel that's been sitting in my closet waiting to be cracked open....
For all my previous books I faxed or e-mailed sketches to the publishers, so this will be my first time actually assembling a physical book dummy. It should be quite a learning experience and I'm looking forward to it!