Another thing that some instruction books say about binding - "stop stitching 1/4 inch from the end" - before doing the folding for the miter -
which works fine if that is the seam width.
I trim the sandwich before putting the binding on - and my seam allowance of the binding is 1/2 inch - so I stop stitching 1/2 inch from the end (or even a thread or two more than 1/2 inch).
If one stitches into the seam allowance of the next side - the binding can't fold back properly.
Stop Stitching Here - - -