I do my piano key borders as leaders and enders. I am making a nine patch quilt from 12 different men's shirts with a piano key border. After I cut all the longest strips that I could, I used whatever was left to cut the keys 2 inch by 4 inch. I have them in a box and just keep pulling out 2 at a time to sew together, I then join the 2's to make 4's and 8's etc and so far have managed to keep them fairly random. I think I will have the border finished before I finish all of the nine patches.