That's an awesome heel formula: the pair of sox I have OTN for husband will have this heel. Thanks for sharing! :inlove:
Since you've got your inch done:
On the heel side of your sock, with the RS(knit side, I'm assuming your sock is stockinette) facing, k to the last 2 sts, the work the TSK. Turn, then purl to the last 2 sts, and work the TSP. This progressively shortens each row you knit for the heel.
Do this until you have 10(narrower heel) or 12(wider heel) sts, ending on a purl row. Turn.
You'll have an upside down trapezoid OTN hanging from the leg of your sock.
Now you'll work the "boomerang" rows, by knitting to the first twin stitch, and placing a marker. Do not turn here. Knit each twin stitch up the side of the trapezoid as 1 st. Turn.
Purl to the marker, slip the marker and purl to the next twin st on the other side of the trapezoid, and purl the twin sts as 1 st. Turn.
Boomerang rows are named that way because they go from ankle bone to ankle bone around the heel in a boomerang shape.
The Build 2nd half of heel part is just the reverse of what you did here, but joins the trapezoids together one TSK or TSP at a time.
Please let me know if the designer says I got it wrong!