Although cutting up a book seems like sacrilege to me, I was luckily provided with old pages from broken books.
My pages measured 8 x 5 inches, so I drew out 5 strips one inch wide.
I then measured each strip one inch less than my starting one (8 inches), so I had 5 strips at lengths 4, 5, 6, 7 and 8 inches long, 1 inch wide.
You can also cut some coloured card to mix in!Starting with the smallest strip on the outside, place the next ones on top going in height order and then work your way back down to the smallest strip.