I quilted a vintage quilt for a cousin.... she didn't know who had pieced it but it was made from shirts. It was stunning. All the shirts were blue or tan and they looked like they were dress shirts. Anyway, the fabrics were stitched together like keys on a piano with sashing between the rows. The keys were about 2 1/2" or 3" wide (before piecing) and 6" long. The sashing was a contrasting color.
I wish I had a picture...... but don't... sorry. Good luck with your project.