[COLOR=DarkOrchid][SIZE=3][FONT=Comic Sans MS]Gauge has nothing to do with it. It's the number of sts in each round.
Chain 3 to 5 sts, join into a ring. Chain 2. Do 11 double crochets into ring. Join with the Chain 2. Dblc at the base of the chain 2. Do 2 double crochets in each of the dblc in the previous round, join. you should have 23 dblc and one chain 2 in the second round for a total of 24.
Ch 2, dblc at the base of the ch 2, dblc in the next st. 2 dblc in the next st, 1 dblc in the next st repeat around, join. There should be 35 dblc and the beginning ch 2 for a total of 36.
This should give you a nice flat circle.
Ch 2, dblc at the base of the ch 1, dblc in next two sts. 2 dblc in the next st, dblc in each of the next 2 sts repeat around, join. There should be 47 dblc and beginning ch 2 for a total of 48.
You can see a pattern emerging here: 2 dblc, then either 1, 2, etc dblc in each of the next 1, 2, etc sts. As long as you continue adding a dblc between the 2 dblcs you'll have a flat circle.
When you want to start curving down for the hat, just crochet even around the hat, keeping the number of sts the same in each round.
Here is the pattern written out.