How to use Fdc to make an opening or underarm

In this video I show you a technique with Foundation Double Crochet Stitches that I use in my Cande Pullover to make the underarm when separating the Body from the sleeves while working top-down.

You can also use this technique to make the opening for a pocket when working with double crochet fabric or for making the opening for an after-thought heel in socks.

Although in this video I use double crochets, this could work with any other stitch such as half double crochet or triple crochet.