Had to pin, because I always seem to forget where I put the instructions on how to do this. Mitred corner border technique This is so easy to do and gives your quilt and borders that wonderful finished effect.
This quilting tutorial will show you how to make borders with mitered corners. Mitered corners look great on all kinds of simple quilt borders. They are easy to make and add a professional touch to your quilt.
Sewing - Handy trick from Cluck Cluck Sew - "Triangle Corner Trick". Instead of drawing pencil lines from corner to corner, place tape along the bed of your machine in line with your needle, and keep your corners in line with that instead!