cathy
LOL - yes, that is me in the pic.
i like to tape down my quilt back making it really smooth. i use gaffers tape but painters tape works just as well.
i tape down all the corners and the center of each side. if the quilt is super big i would even tape in more locations.
then i lay down the batting and smooth it out (like a nut) and tape it to the quilt back, then i put down the top and smooth it out (like a nut) and tape it to the batting.
then i slide the marble under the backing. it pops up the sandwich just a tiny bit so that you can put the pin thru with ease.