Stop sewing 1/4 from the corner; fold your binding strip with 90 degree angles and tuck under your already sewn side. Start sewing next edge 1/4" away from corner. Repeat with all 4 sides. When you are ready to flip to the back and sew down be sure to clip your quilt corners at a 45 degree angle to reduce bulk.

I don't normally have issues with the miters but if they are being particularly cantankerous, put a pin through the miter until you've gotten the back sewn down. If need be, put a stitch or two in the miter to hold in place.

That's the same video as the link I posted above. When I looked at it on youtube it said not to share from there but yours doesn't. Weird.

eta: when I followed the link I posted and then the youtube link on the page it no longer says not to share.

my tip is to try folding the miter both ways. lay the top down and fold the side at 45 degrees. Then fold the side flat and fold the top at 45 degrees. one way always lays flatter. (my friend said it is opposite from the back, but then there is always that one rebel miter that does it the same direction!)

It seems like each process of making and binding a quilt is open to how it feels best to you and if the finished task is done well. It is like cooking all good recipes but the cooks are happiest using their own way of doing it. I forced myself to read, watch videos and practice a long time before I was happy with my bindings. I only use a bias binding when the edges are curved or inverted and need a gentle stretch or encouragement to conform.

Go to YouTube and look for MSQ Jenny Doan " the perfect binding tutorial". That is the method I use and she shows how to do it step by step with great camera angles.

I make mine sort of like Patrick Lose's method but I have never tried the 45 deg. angle that he makes when he comes to a corner & clip out the excess fabric. I will try that next time (if I remember to do it...:)).
Watson, this was a good question for the board.

its those 3 - 5 stitches to the point that changed my mitering
https://www.youtube.com/watch?v=Vci9-li3aYU

Thanks for all the really great information here. I have been using Patrick lose' method of removing that extra fabric for a
while now and am very satisfied with how much it helps. I will be going back to watch all the other information. QB is a great source for help. TFS
peace