I cast on 72 stitches and knitted 20 rounds of 2 x 2 ribbing. Then I started the Reversible Rib stitch:
rnd 1: k2, p2 rpt from
rnd 2: p1, k2, p2 rpt from, ending with k2, p1

This creates a ribbed pattern that has a column of stocking stitch and a column of reverse stocking stitch flanked by columns of garter stitch. The ribbing is very stretchy, very textured, and looks identical on both the public and the private sides.

I decided to knit a traditional heel-flap-and-gusset heel and continued the rib pattern down the heel flap with 3 stitches-worth of garter stitch on either side of the heel flap. I knitted the heel flap on 35 stitches, arranging the stitches on the needles so that the first knit stitch was moved to the third needle, becoming the last stitch on the instep. The pattern for the heel flap:

(I started the heel flap after completing a round 2.)
Row 1: K3, K2, P2 repeat from to last 4 stitches, K4
Row 2: K3, P2, K2 repeat from to last 4 stitches, P1, K3

I knitted 38 rows (19 purl ridges on the garter-stitch edges), turned the heel, then picked up and knitted 20 stitches along each heel flap edge (1 stitch in each bar plus one between the heel and gusset so there would be no hole).

I worked the heel gusset decreases 15 stitches in from the instep on each side of the heel every other round and decreased down to 35 stitches. This left 3 heel stitches between the decreases. I used the instructions from the Breaking Hearts Socks to do this heel. (BTW, I highly recommend the Breaking Hearts Socks pattern. At only $5 USD is it a bargain.)