Align the granny squares with the right sides facing out
Choose a joining method: whip stitch, slip stitch, single crochet, or flat slip stitch
Thread a yarn needle with matching yarn for hand sewing methods
Hold two squares together edge to edge
Insert the needle through the outer loops or back loops of both squares
Pull the yarn through gently to join the edges
Continue stitching evenly along the seam
Keep stitches consistent in size and tension
Fasten off securely at the end of the seam
Weave in all yarn ends
Repeat until all squares are joined
Block the finished piece if needed to even out the shape