That is the best tutorial I've seen for making miters using the original method. I still find that stripes are difficult to match with that method.
About a year ago I posted a tutorial on the easy method I developed to make borders easily that lets you match stripes on all corners. My method has you make the measurement for the length of the border, cut the 45 degree angles before you even put them on the quilt-no different than fussy cutting any fabric. Works especially well for multiple borders and works every time.
10-10-2011
Easy Mitered corners-even with stripes