Using bulky yarn.
Cast on 96 on 4.0mm needles.
Switched to 4.5mm for the chart.
Four repeats of the chart.

Started decreases right after the chart ended.

K4, k2tog.
K3, k2tog.
K2, k2tog.
Knit one row.
K1, k2tog.
K2tog.
Knit 1 row.
K2tog.
Thread yarn through a needle and pull all stitches together.

I sewed a button on the inside of the hat and pulled the elastic from the pompom through. This allows the pompom to be removed if the hat is washed.