By now you have knit the cuff, the leg, created the heel flap, turned the heel, picked up stitches and knit the heel gusset, and completed the foot of your sock to within 2 inches of the finished length.
You are on the last "leg" of your journey, with the toe decreases. You have 1/4 of the stitches on each of two sole stitch needles (needles 1 and 3) and 1/2 of the stitches on your instep needle (needle 2). Your knitting begins in the middle of the sole, on needle one.
Row 1: On needle one knit to 3 stitches from the end of your needle, knit two stitches together, knit the last stitch on this needle. On needle 2, knit the first stitch, slip the next two stitches and knit them together (ssk), knit to the last three stitches on this needle, knit 2 together and knit 1. On needle 3, knit the first stitch and ssk, the next two stitches, knit to the end. (4 stitches decreased)
Row 2: Knit all stitches, remembering to pull up firmly as you knit the sole stitches. You will no longer use k2 p2 rib on the instep stitches. This will give a smooth, seamless toe to the sock which will be comfortable to wear.
Continue in alternating row 1 and row 2 until 16 stitches remain. (These stitches will be grafted together using kitchener stitch -- instructions coming in the next installment.)