My most recent is this black and white fabric-covered book with 5x7 pages that alternate between black and white throughout. I used a new-to-me binding stitch. I'm sure this stitch has a name and that many others use it. But I didn't get it from a book, I didn't search online for a tutorial. Instead I figured it out on paper, along with another couple stitches, and then tried them. The photo below are my little test books from the day before, trying out two of the stitches.
Am I having fun yet? Need you ask? I already have half a bookshelf filled with handmade books. I'm on a roll.