The double crochet stitch is most commonly used in granny square, filet, and corner to corner (C2C) projects. It is also used for different shells and clusters.
The first dc of any new row will usually be a chain 3. There is a way to do a beginning double crochet in place of the chain 3, but for now, I will just cover the basic stitch.
How to make the double crochet stitch
Yarn over (YO), insert hook into stitch in row below, YO and draw up a loop (3 loops on hook). YO and pull through 2 of the loops on your hook (2 loops remaining). YO and pull through final 2 loops on hook.