This is where your sock begins to look like a sock. You will need to know how to purl two together (p2tog) which is easy peasy and slip, slip, knit (SSK) which is a tad more difficult. SSK gives a left slanting decrease stitch and is often used in sock design and lace work. - have a look at the video to see how it is done.
SSK - slip slip knit.
• Slip a stitch off the left needle without working
• Repeat with the next stitch
• Put the tip of the left needle into the front loops of the two slipped stitches. Wind the yarn anticlockwise around the tip of the right needle and knit the stitches together. You have now decrease by one stitch
Now watch the video on how to turn your heel. Here is what the pattern looks like written down. Always slip the first stitch of each row.
Turning the heel of a sock – full instructions
Finish your heel flap with a knit row (so that the next row is a purl row)
Row 1: slip first st, p 16 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
Row 5: slip first st, p8, p2tog, p1, turn
Row 6: slip first st, k9, SSK, k1, turn
Row 7: slip first st, p10, p2tog, p1, turn
Row 8: slip first st, k11, SSK, k1, turn
Row 9: slip first st, p12, p2tog, p1, turn
Row 10: slip first st, k13, SSK, k1, turn
Row 11: slip first st, p14, p2tog, p1, turn
Row 12: slip fist st, k15, SSK, k1, turn
You should end up finishing on a knit row and have 18 stitches