Corner to Corner (C2C) Box Stitch has become a hot stitch over the past few years. It can be used to make a square or rectangle of any size with pretty much any yarn. Plus it is made of blocks so it can be used to create graphed images. Once you have this stitch down you can take a graphed image (such as a cross stitch pattern) and crochet it. So cool!!
Get the free crochet tutorial here: https://jessieathome.com/double-crochet-c2c/