My first quilt ever was a GFG and done by hand, so "Y" seams are not a problem, but when I do them by machine, I sew almost to the "Y" and stop, then go back with needle and thread to properly sew them by hand since I can't seem to do it by machine very well. Basically I just do a stitch or two to finish the seam and then finish the other two seams, using a single back stitch to secure the "Y".