Stay tuned for this knitting instructional video on inserting a heel for a knitted sock. This is a very large scale knitted sock. It's going to be a felted Christmas stocking. The knitting is finished except for inserting the heel. The knitting technique demonstrated is exactly the same for a more normal, human-size knitted sock. It's also the same technique used to insert a pocket in a sweater.
When I finished knitting the cuff, I knit the back stitches with waste yarn (yarn left over from another project). To insert the heel, the waste yarn is removed and the stitches above and below are re-captured on needles.
I like to use the tip of a double-point needle to carefully remove the waste yarn. If you're faint at heart and worried about dropped stitches, you can slip each exposed stitch onto a double-point needle as you remove the waste yarn. I like to completely remove the waste yarn and then pick up the resulting loops.
When you've picked up all the stitches, you'll have two parallel needles, each holding half the stitches. For a heel, you want to pick up one more stitch at each end of both needles. This will prevent a hole in the gap between the needles.
Now you'll follow the knitting pattern directions for distributing the stitches and knitting the heel. Heel shaping is usually done exactly as for shaping the toe of the sock.
Hope this knitting tutorial video helps you improve your knitting skills!