I started using monofiliment on top and matching thread on bottom. I started using the same on top and bottom when I learned how much softer/cuddlier the quilt is with out monofiliment thread. As for the "non matching" of thread and fabric, I try to match as much as possiable, but if not, oh well! I have not had a quilt given as a gift returned because the thread didn't match every fabric.
D