You merely make 4 or 6 layers of the batting and then using your ruler, cut the size of square into the strips and then cut the strips into squares. Just like you would do for the fabric. It really isn't that different. If you are using a thick batting, less layers at a time. Remember the batting doesn't have to be perfect when used in a rag quilt, so go for it and save some time and trouble when cutting your batting.