While I did not use a specific pattern for the brim of this hat, and had to make several changes due to the difference in yarn size, you can get the basic pattern idea by looking here. I made it with bulky yarn and a 5.5 mm hook. I started with six puffs at the top and increased each row until it was the appropriate circumference. I then worked the hat in even rows until it was about .5" from the length I wanted. I then did one row of sc and three rows of camel stitches.