I use much the same method as Patchsamkim taping my backing to the large tables in the church or community hall. I pin with safety pins but also pin with straight pins down the seams. I use Stich in the Ditch down the seams to anchor everything and then go ahead with the rest of the quilting. I run one machine quilting line right through the quilt both vertically and horizontally to start and then quilt in sections using a walking foot smoothing and stretching with my hands (moving pins if I have to ) as I go. I rarely get puckers using this method. Although as my daughter has frequently reminded me "Mom, the baby won't care about a few puckers!"