When I make a rag quilt or a Cathedral Window I like to put the batting in the center of the square at the very beginning. That way I can use smaller pieces and my quilt is completed much faster. I use light and natural batting so when I make a log cabin quilt, I sew the fabric directly to the batt. When I sew the squares together, I trim the batting so it isn't overlapping. Then I just tie the quilt after putting the backing on.