I also have gotten a lot of ideas for ATC making. One of which was for an ATC book. The original Pinterest pin was about APCs (altered playing cards) and it was not a tutorial, just showing the finished accordion style folded booklet. But it really really got me thinking.
I am doing a monthly ATC trade over on Atcsforall.com. The original trade agreement was for 2:2 cards, with the design being up to whatever the artist feels like. It has however evolved into something much more from here, I sent her a few 9 card polyptychs (?) since then, she got me hooked on rolos and made me an awesome canvas, too. We just try our best to make this trade something special.
So for our November trade I decided to make my partner an ATC booklet. I used my trusted inktense pencils for the background, but also my new Promarkers and Sharpies for colour pop. I had no pretty jump rings at my disposal so I had to make my own from sturdy wire, but I think it worked out fine. On the back of the cards I wrote her a letter, but I am not going to show that here...