knitting a waistband

facilitate folding down to the inside of the waistband. I have completely forgotten how to knit the last row of the waistband to the inside of the nether garments. I am knitting nether garments by Elizabeth Zimmermann, from the bottom up. I have knit the waistband with a purl row at the top to fold over flat and attach to the inside of the body. I did this on another pair of nether garments I made 6 years ago, but cannot remember how I did it.I have forgotten how to set up my needles and yarn, as well as how to hold my knitting and proceed with attaching the bottom of the waistband to the inside of the garment. I have also forgotten how I managed the elastic placing as I knit. I did not sew the waistband closed; I cast off while knitting the waistband closed. I appreciate any help anyone can offer. Thank you.

This is such a neat way to finish a hem. Here’s a video (see especially 6:30min).