Butterly Stitch Slouch Hat - Meladora's Free Crochet Patterns Tutorials: LOVE THIS HAT! Best pattern I've found for a slouch hat and Meladora's crochet videos are great! Check her out at the link. She is amazing!
When a “bird’s nest” of thread appears, the likely culprit is your upper thread tension. If loops appear on the underside of the fabric, the upper thread tension may be too loose. If knots appear on top of the fabric, the upper tension may be too tight.