When I am binding a quilt.....I cut 3" strips enough to go around the quilt. Fold the 3" strip in 1/2 and sew the raw edges together..this is a 1/4" seam......I leave the last 4"open for joining. Take the now 1 1/2" strip the open end.......I lay it on the front of the quilt at the outer edge. I have the 1/4" seam to follow as I stitch. I pin to the 1st corner because I am going to stop there. As I get to the corner....I have made sure there is no extra slack in the binding......I sew to the 1/4 away from the corner. I use the back stitch 3 stitches. I pin at the 1/4" so I know where to stop. My pin follows the angle I want to maintain like I want the miter to go. I fold the fabric of the binding back over its self....FORM an L...BE SURE the corner is square with the edge of the corner of the quilt. This is where the problem gets us. The binding needs to be square with the corner of the quilt. The long side of the L is where you were previously sewing. The short side of the L is the binding folded back to the right. Then I mark with a straight pin where I want to start sewing on the corner.... This is also pinning just like I want the angle to be, leaving the 1/4 " open. I stitch 3 stitches and back stitch 2 stitches. Make something small to practice on Go slow, IT is only fabric...not arms and legs.....You can do it. It is up to you 2 1/4" or 3". This is how I was taught. Maintain that pretty L in the binding and you should have no problem. I had a great teacher and I do good work so please.....NO QUILT POLICE