I tend to knit socks using the magic loop method on 100 cm circular needles. These directions are best suited for this method but easily converted to using dpns.
I cast on 60 stitches with 4 ply/sock yarn on 2.5 mm needles. Arrange 30 stitches on each half on a magic loop.
I knitted 2 x 2 rib (k2, p2) for one inch.
Knit 2 rounds.
Next round, k1, p1 for one round, then knit 2 rounds. Repeat the last three rounds to form the pattern.
Knit in this pattern for 7 inches.
For the heel flap, work on half of the stitches only. (work on one side of stitches - that's 30 stitches) back and forth in a slip stitch pattern.
Row 1 (RS): *Slip 1, Knit 1
Row 2 (WS): Slip 1, Purl to end of the row
You will be working back and forth on these 30 stitches and repeating row 1 and 2 a further 14 times.
(You will have worked 30 rows in all).
To Shape the Heel:
Row 1: Slip the first stitch, p16 sts, p2tog p1, turn
Row 2: Slip first st, k5, ssk, k1, turn
Row 3: Slip first st, p6, p2tog, p1, turn
Row 4: Slip first st, k7, ssk, k1, turn
Continue in the same way by taking in one more stitch every row until all the stitches from the heel flap are included, you will have 18 stitches on this needle.
Knit across the heel, pick up 16 stitches from the side of the heel flap. Pick up the slipped chain like stitches and pick up an extra stitch if you have to for the gap between the heel flap and the top of foot.
Knit across the top of the foot in pattern (30 stitches)
Pick up the same amount of stitches on the other side of the heel flap (make sure there is no gap again)
Round 1: Knit across gusset until there is 3 stitches left, k2tog, k1 and before the top (the pattern part) section, knit across front in pattern, k1, ssk, knit across rest of gusset/round
Round 2: Knit across gusset, knit across top section in pattern, knit till the end of the round.
Repeat these two rounds until you have 30 stitches left on the bottom section and the 30 stitches left for the top patterned section.
Knit sole (bottom) stitches and knit in pattern the top section (pattern section) until the foot measures 2 inches less than your desired length of the heel.
Round 1: K1, ssk, k to last 3 sts on back, k2tog, k1. Repeat on back of foot.
Round 2: Knit around.
Repeat rows 1 and 2 until you have 12 stitches on each half/24 stitches in total
Then graft the two sides together using the the kitchener stitch.
Repeat for other sock.