suppose you see a pattern you like that isn't designed especially for fat quarters.
let's say it calls for one yard of fabric A. instead of buying a whole yard of something, pick four fat quarters of the same color. different prints, could be different shades, but same value. different but similar.
do that for all the fabrics in the quilt.
then cut your pieces from the fat quarters as though it was yardage.
clear as mud?