The quest for the plainest of plain hats.

Setup: Crochet cast on in ravel cord, 132 stitches.
Knit with actual yarn.
K1 P1 for 8 rounds. This makes a very short edge.
Slip 1 (with yarn in back), p1 (transition round)
Switch to larger needles and stockinette your brains out.
When hat is around 4” high, start decreases.

Decrease 12 over four rows: in the first row, decrease 6 times using evenly spaced k2tog, next round plain, third round decrease 6 times using ssk so that the decreases stack (specifically, the stitch you knit into before passing the slipped stitch over should be the one directly above the k2tog), next round plain.

Specifically:
Repeat 6 times: k10 k2tog k10 (126 stitches)
k around
Repeat 6 times: k9 ssk k10 (120 stitches)
k around
k9 k2tog k9 (114)
k
k8 ssk k9 (108)
k
k8 k2tog k8 (102)
k
k7 ssk k8 (96)
k
k7 … k6 (84)
k6 … k5 (72)
k5 … k4 (60)
k4 … k3 (48)

k3 k2tog k3 (42)
k
k2 ssk k3 (36)
k

Now(ish) stop doing the plain spacer rows
k2 k2tog k2 (30)
k2 ssk k1 (24)
k1 k2tog k1 (18)
ssk k1 (12)

Thread a needle through the stitches, you’re done!