I made the up as I went using my basic sock math.

Cast on 40 stitches then knit 5 rounds of 1x1 ribbing.

Switch to 2x2 ribbing for the ankle portion.

Used 20 stitches for the heal flap, slipping side stitches until there were 11 on each side to pick up. Turn the head with only 6 stitches remaining in the middle.

Pick up 11 stitches on each side.

Knit length of foot.

Standard decrease for toes until 8 stitches remain on each of the 2 needles. Kitchener the toes closed.