Double binding when using backing for binding.
When we were making a lot of charity quilts, we always tied them. Then I trimmed the top and batt evenly, and folded the backing in so that only about 3/8 inch was still showing off the end of the quilt. The extra was tucked under, which made a double binding. In order to get nice square corners, I sewed almost to the corner, turned the next side down at a 45 degree angle, then folded it onto the quilt as it should be, and continued stitching.
I usually used a decorative stitch to hold this backing onto the front, and of course this pretty stitching showed on the back also. I made one with navy blue back, which folded to the front to make the binding, and then stitched a pretty pattern in Red. That was beautiful, and it showed on the back, too.