I literally just finished the Sugar Cone Skully Hat by Julie of Gleeful Things and I LOVE it! It is the worsted weight version of her VERY popular Waffle Cone Slouchy Hat. This pattern was super easy, all single crochet and double crochet. There was an error in the 4th round, but one that is super easy to correct. The pattern calls for an H hook and you are supposed to check your gauge after the 4th round. I cannot stress how important that is with this pattern! That round is supposed to measure 5" in diameter, and mine was barely 4". So I frogged and switched up a couple to a J. It still came out just shy of 5" but just barely. I finished it with this hook and it came out perfectly. After that 4th round, the pattern stays the same until the brim, so it would be easy to add a few rows to make it "slouchier" if you wanted. I think it would be easy to adapt, too, for bigger heads, or for lighter weight yarns that would need a bigger starting circle. This one starts with 10 dc per round and and expands to 40 with ch-1 spaces.
I used Hobby Lobby's I Love This Yarn Prints in Pomegranite Stripe and it was perfect for this, not to mention that this yarn, although a house brand, works up well and stands up well and comes in at about $3.99 a skein. I probably used a bit less than half of a skein, less than 126 yards. You can click the link to see bigger pictures in a new window.