I use thumbtacks. Put a few tacks thru the right side of the backing fabric
at the points you want to match and cover the heads with masking tape to
keep them in place. Lay the backing down on the table. Add the batting,
then carefully place the top, using the tacks to align. I personally would
add some pins as spray basting does not really adhere the quilt top to the
backing fabric and the batting layer can shift some. Remember to remove
the tacks before quilting.