"Flat Braid" Square Joining Method for granny squares. Creates a lovely edging! Another method of joining squares, a simple ch 3 interlocking, done as the last rnd on the squares. Join as you go, could not be easier.
If you're looking to learn how to crochet granny squares, then you'll definitely want to check out How to Crochet: 16 Quick and Easy Granny Square Patterns. This free eBook is filled with unique granny square patterns in a variety of colors.