I like a peiced backing if I'm keeping the quilt; gifts I always try to coordinate with the front if not match those colors.
I just finished a wall hanging and used 3 different greens I had that were WOF but only 15 or 20 inches wide; I've had these fabrics since I started quilting and decided I don't want to cut on them any longer. I have some yardages I think I'll do the same with