I couldn't seem to find an earflap hat pattern I liked (or had come out right) so I made my own pattern, having made a few hats now.
Needs: 5.5 mm hook (for tight stitches) or 5 mm hook (for looser stitches) to achieve size and worsted/aran weight yarn.

Notes: Each round is joined with a slip stitch and then chain two to start the row.
dc: double crochet
dc2tog: double crochet 2 together
sc: single crochet

Start with a magic ring or the chain 2 method.
Rd 1: 9 dc in the ring/chain.
Rd 2: 2 dc in each stitch around (18 sts).
Rd 3: *1 dc in 1, 2 dc in next st* 9 times (27 sts).
Rd 4: *1 dc in 2, 2 dc in next st* 9 times (36 sts).
Rd 5: *1 dc in 3, 2 dc in next st* 9 times (45 sts).
Rd 6: *1 dc in 4, 2 dc in next st* 9 times (54 sts).
Rd 7: *1 dc in 5, 2 dc in next st* 9 times (63 sts).
Rd 8-14: dc in each stitch around (63 sts).

Flaps:
1: Ch 2, dc in 12 sts.
2: dc2tog, dc 8, dc2tog (10 sts).
3: dc2tog, dc 6, dc2tog (8 sts).
4: dc2tog, dc4, dc2tog (6 sts).
5: dc2tog, dc2, dc2tog (4 sts).
Fasten off. Count 20 sts, join yarn and repeat for second flap. Sc edge onto hat. Add tassels, spikes, pom poms, mohawks, or what ever you like!

This pattern belongs to me. Any reproduction of the pattern is forbidden. The final product is yours and may be sold, though.