I used to make the backings perfectly match the front or at least nicely compliment it. Then I went to a class and she had quilts she used the leftover fabric from the front in odd sized squares,e tc. Came out really nice. Or if you demand excellance you can make even blocks etc. And then the show quilts....Last year I pieced the back to match the front and actually passes the scrutiny of the judges and still got a check+. Whatever trips our triggers, I guess