I recently discovered the work of France Papillon who does the most amazing journal pages. This is the result of a little online course I followed. It is four sheets of A4 watercolour paper, the backgrounds were done first then the pages folded and sewn together using a simple pamphlet technique. I then continued to work into them.
I loved the course I did with Roxanne Evans Stout which resulted in my Four Seasons book, so have done another course with her to produce a Nature Journal.