Here are three “fairy bonnets” that I made using a pattern I bought off Etsy. It’s a very simple, easy pattern. The bonnet is worked flat and then sewed up the back. You can do it with one ball of yarn if you are making a child’s size. In this case, I used cotton because these were meant to be spring bonnets for some little girls I know.
It’s not good to post picture of kids’ faces, so this Styrofoam model will have to do. As you can see, the corner where the bonnet was sewed becomes an adorable point on the wearer’s head. The wavy, tipsy effect is achieved as follows. On one row, a bunch of extra stitches are added. Two rows later, these stitches are reduced, alternately using Knit Two Together (which tends to lean right), and Slip-Slip-Knit (which tends to lean left).
I later made a navy-blue version of this same bonnet, and then completed one with a varicolored ball of yarn. They knit up quickly and make good gifts. (At least, I think they are good gifts!)
I am experimenting with adding a large button on one side and a crocheted loop on the other, rather than the long knitted tie strings, which look cool but might be inconvenient. I’ve had good luck with the button/loop arrangement on bonnets I’ve made for myself. The loop is less obtrusive than a string or a tassel when the bonnet is not fastened, and you can pull the loop across and hook it around the button one-handed if you need to.