Start with a pair of knee high socks
Make 4 cuts in socks - see below
Take the largest portion of the foot and reverse fold so that the right sides match. Then sew lengthwise and turn rightside out to form a cuff.
Turn the leg portion inside out and then place the cuff inside until all 3 rough edges match. Place 3 edges in sewing machine and sew them together. I went around the cuff 2 times to ensure it held.