I made this little notebook (mine is 2" x 4") from a used manila envelope. It utilized only things I normally throw away and I think the postage makes an interesting cover.
1
Choose which page to use for the cover. Reinforce the inside by gluing card inside cover with stick glue.
2
This is what your cover should look like at this point.
3
Stack your pages. Punch two holes through the fold of each page.
4
Sew the pages together.
5
Using stick glue, attach the back page to the inside cover. You could do the same with the front, but I choose to attach only the back.
Using stick glue, attach a small scrap of paper to reinforce the "spine" area.