Crochet: 12 ways to join granny squares from Baking Outside the Box: pt 1 'The Lost Granny Squares' , joining tutorial roundup.
Wool n Hook - Invisible Seam (Reverse Mattress Stitch) Joining Crochet Squares
12 Ways to Join Granny Squares Invisible stitch to join crochet blocks tutorial.I wish I would have seen this before I finished my Granny square blanket
Join Crochet Motifs with One Seam from Crochet is the Way - Learn this seamless joining technique for your square or rectangular projects . Get the link for this pattern and more at Hookin' on Hump Day.