I found this free pattern on Ravelry.com.  You will have to create a sign-on to access the patterns.  It is made for raffia but I crocheted it with Red Heart Super Saver yarn in black.  The instructions say to use a size 3.5mm/E hook but I read that it turned out VERY small so I used a size H hook.

I have a very small head so it ended up being to big for me but will give it to a friend. I also did not crochet to row 31 for the sides but stopped at row 24.   The hat ended up being approx 24″ circumference and I measured my head at 20 1/2″.  I will be crocheting it again and try a size F hook.

This turned out to be a very quick and easy hat and here is a row that you can add a ribbon if you want.  If you like hats give this a try!