How to Crochet a puffy spike crochet square

The author of this video explains how to combine a puff stitch and a drop stitch while crocheting a six by six inch square. She goes step by step, first showing how to create a slipknot, and then by showing how many slipknots will be needed in each chain across the square, which make the foundations. She then shows how to make a slipknot of a new thread of yarn, and how to insert it on the hook, into the original chain while creating the puff stitch. The chains are repeated, as are the puff stitches, and she shows where and how to end each stitch and chain before moving on the the next chains.