I have just finished the third book from an online class with LK Ludwig (class info here). This is a great class, three for $15. Can't beat that!
My third book is the Seed Pearl stitch. I just wanted a quick sample book for myself, but in retrospect, I should have used some real cords. Instead, I used some old paper twist (? drawing a blank on what it is called) that was in a bag of stuff to get rid of. Seemed like a good idea at the time - it was sturdy enough, handy, and I could fray the ends when done and fan the paper to make an interesting cover.
(In case you are wondering, book 2 is the wrapped straps, and my sample is in the Nov 4th post. Book 1 is sewn over tapes, which is what I've used on all my stencil books and is in LK's book Creative Wildfire. The sewn over tapes really has become my go-to technique lately!)