Here is a follow up to the easy mitered borders. I love to have a narrow border to stop the movement of the quilt before the striped border.
LIne up the stripes with every other strip face up or face down as with the single border.
Set up to cut the 45 degree angle on one end of the strips.
Cut the angle through all strips at once.
Sew the narrow border RST on the top of each strip.
Press the seam toward the narrow strip on the 1st one, down on the 2nd, up on the 3rd, and down on the 4th.
Layer all four pieces, line up the 45 degrees on the ruler along the original cut, and continue the cut through the narrow border. After this you are ready to measure the center of your piece and continue with this "set" as if it were a single border. Measure, subtract 1/2", and cut the other end. Ready to apply.