What a fun project! I made mine from a sheet of mixed media paper 18x24". How freeing to just pull out supplies and have a go at a large sheet of paper. 

I used kuretake watercolors, art graf, gelatos, blackwing pencil, and arrtyx markers.

I had handmade paper for the cover and a little piece of chenille yarn for a tie.

I left the back side of the paper blank, made 3 cuts, and glued (uhu stick) only the pieces where there was a 90° fold (I want to be able to eiher add some other artwork to the backside - smaller pieces per 'page' and glue in - or just work the art directly on the book 'page')