When I prepare backings, I press and starch them. Then I lay them out on three tables shoved together (for a large quilt) and use masking tape to stick the backing securely to the table. Then I set my batting on top, smoothing and patting down and finally add my top, pinning with safety pins all over. I also use straight pins placed horizonatally to the seam, lengthwise down my main seams both horizontally and vertically. I stitch these main seams first, to anchor the quilt before tackling any of the interior parts. I use my hands to smooth and feel for wrinkles as I go along. Stitching these main pinned seams first has really helped to eliminate puckers. I occassionaly get a few but this method has practically eliminated them.