My notebooks are 3 1/2 inches tall by 2 1/2 inches wide, so I started by cutting plain white copy paper into 3 1/2 by 5 inch strips. I used a paper trimmer with a small sliding blade, but you could easily use a ruler to mark straight lines and cut with a pair of scissors. I cut six strips of paper for each notebook, which when folded will create 12 leaves or 24 pages total.
For the covers, I chose patterned scrapbook paper in a slightly heavier weight--these happened to be double-sided, which created a neat endpaper effect! I cut the covers 3 1/2 by 5 1/8 inches long, since the cover has to be a bit bigger to go around the layers of folded paper. This was actually a little too short still, so I might try making the cover strip 5 1/4 inches next time.
To bind the notebooks, I opened and stacked the pages and used a 1/8-inch hole punch (not a standard 1/4-inch, which is too big) to punch two holes in the middle fold, going through all six sheets at once. Then I lined up the cover on top and punched holes in the same spots, since the cover is thicker and I didn't know if the punch could go through it and the paper together.
I think these miniature notebooks would make really nice DIY favors for parties, showers, and weddings, especially if you label them with each guest's name. You could also use them as a thoughtful alternative to greeting cards, perhaps handwriting favorite quotations or making little sketches on the pages. Or, just make them for yourself to keep in your wallet or purse for handy miniature shopping and to-do lists!