You can make one any size, but my goal here is to make one that could fit on a standard card. I started with a plain piece of white cardstock, about 4 inches long and about a half inch wide. Using scissors, trim away a slender neck and shoulders. The neck looks long now, but most of it will be hidden under the head.
Next, prepare a small piece of paper to be the undergarment - kimonos are not worn directly against the skin. I used a 2 x 3 inch piece of leftover origami paper.
Pick a a paper to be your kimono. Although most people wrap the kimono all in one piece, I find it easier and less bulky to wrap the top and bottom separately. No one will see once you put the obi (sash) on. For this size doll, I cut a 2x4 piece for the top and a 4x4 piece for the bottom of the kimono.
Fold over one edge and color the small piece just like you did for the undergarment. Wrap it around the neck, letting the undergarment show at the neckline. Again, be careful about having the right side over the left.
Fold the sides back to be parallel to the sides of the base. If you are making a freestanding doll (not glued to a background piece) tuck the excess paper inside the fold instead of pushing it to the back. Use a little adhesive to hold the top in place.
For the bottom of the kimono, fold and color one side of the square of paper, just like you did on the first two pieces.
These dolls ended up being about 6 inches long, but if I wanted to fit them on a card, it would be easy enough to trim a little off the bottom. You may wonder about the lack of sleeves. Bookmark dolls traditionally don't have sleeves. However, it is your doll. You can try to add sleeves if you want, but trust me - it will not improve the look of your doll, unless you want your doll to look like Batman.
The obijime (thin tie over the obi) is a very thin strip of yellow cardstock. What Japanese girl doesn't have a headband with kitty ears? Anyway, as you can see here, if you make the doll out of scrapbook paper, it will be sturdy enough to stand up. the wings...er...sleeves are two separate pieces of 3 x 6 inch paper folded in half cut with a curve.
I hope you will give this a try - it is fun, and a great project to do with the kids, too.