This knitting technique video tutorial demonstrates how to do Judy's Magic Cast On, which is a common way to start knitting a toe-up sock, but is also used for knitted mittens and other seamless projects worked in the round. The video shows how to set up and work the cast on so that no stitches need to be knitted through the back loop to untwist them on the first round, and includes instructions on transitioning to knit in the round at the end of the cast on.