I haven't posted here before, so bear with me. I am making a quilt and want to add three borders. First border is 2 1/2 ", second border is 1 1/2", outside border is 4 to 6", haven't cut it yet. What I need help with is, do I sew all three borders together and then attach to quilt top, and then miter the corners or do I attach borders one at a time mitering each corner as I go? I have not made mitered corners before. Any help would be appreciated.