I clamp my backing to my cutting table with alligator clamps and pull it taut. Then I put on the batting, smooth it out and put it under the clamps with the backing, keeping both taut. Then I center and smooth on my top. I pin from the center out with safety pins, using at least one in each corner of every block and one in the center of each block. I then release the clamps and am ready to quilt. I have not had any puckers on the back since I started doing it this way.