1. Divide your paper into fours (or whatever size you want the notebook to be).
2. Cut along one of the lines.
3. Score along the other line and fold in half. Make as many pages as you like.
4. Line the papers up and mark where the holes will go on the spine (use a binder clip, clamp, or heavy book to hold them in place). The number of holes and where you make them don't really matter. I made three pairs of holes without measuring between each hole.
5. Pair up the papers so you have stacks (signatures) of two and get out that needle and thread!
6. Tape down your thread on the outside of the first signature (to be glued to the spine later) and thread in and out of each hole.
7. Thread in and out of the second signature to attach and then make a loop around the thread in the first signature and thread through, knotting the two signatures together (see photo below). This is how you'll sew all the signatures together. Again, I freehanded this a bit by just looping and knotting until I was satisfied.
8. Use a clamp or heavy book to hold all the signatures tightly together and brush glue along the spine. I used E6000 since it's strong but doesn't dry hard.
9. Once that glue is dry, cut two pieces of matboard, stiff cardboard, or whatever you like for the front and back cover. I wound up using the back of an old drawing pad (hence the paint). Glue one to the front and one to the back.
10. *Optional: cover up the spine with some fabric or nice paper. I liked the way mine looked exposed so I left it. I'm not sure if a paper spine would hold up to opening and closing, but I imagine fabric glued to the front and back cover (and covering but not glued to the spine) would work great.