I spent some time yesterday in my studio working on a book -- finally!. The result was a small mock-up ( 3 " x 6") of a circle accordion in one of Alisa Golden's books. It's a simple structure : an accordion attached to covers. The covers are attached in such a way that when the book is fully open it forms a modified circle. My variation includes 2 sections with pockets, alternating with two sections without.
I used Canson cover-weight for the cover and some left-over decorative papers for the pages. My only revision to Golden's instructions -- besides the size -- was to use paper strips rather than linen tapes to attach the sections to each other and to the cover.
I enjoyed this so much that I may start working my way through the book, making a collection of mock-ups, then choosing the structures I like best for the next step.