To do a double crochet (dc), yarn over (a yarn over means bringing the hook back and behind the yarn to form a loop). Then insert the hook where you want your dc to go. Hook the yarn and pull it out. You will now have 3 loops on your hook. Hook the yarn and pull it through the first 2 loops. You will be left with 2 loops on your hook. Hook the yarn again and pull it out through the remaining loops.