I have no idea where I learned to do binding the same way, but have been doing it this way since I started making quilts. I do have one little hint to add. When you are trimming the overlap on a bias binding, instead of cutting at the 2.5" line, I cut at the 2.25" line, since moving the quilt binding around to sew it can add a little stretched length. Sew as before. It will still lay perfect for you, but only do this on bias binding. This "missing" 1/4" is not even visible on bias binging.