Don't know if it's the proper way but I can tell you how I layer a sandwich for machine quilting. First I clear off a large space on my dining room floor. I'll scrub it if it looks dirty. I like to use the dining room floor because it has 12" tiles that can be used as a grid. Lay the backing on the floor upside-down and match the seams to a line on the tile floor. Using masking tape, tape it to the floor. Smooth the pre-shrunk batting out on top of the backing. (I use needle-punched batting such as Warm and Natural because you can quilt the rows further apart.) Tape down the batting. Then smooth out the quilt top on top of the batting and make sure it lines up with the floor tiles. Then tape it down. Your goals here is to have all three pieces laying straight and without folds, tucks or puckers. Next place safety pins through all three layers at six to eight inch intervals. Try to put the pins where your needle will not run them over while you are quilting. Remove the tape and you are ready to quilt.