For me, when I get puckers it means I didn't tape my backing down well enough. I'm not as young (or as light) as I used to be and doing all those deep-knee bends to tape down and then baste a quilt just kill me after awhile so I start skipping steps and then I get puckers. I'm going to switch my methods and try something I learned from a Leah Day class on Craftsy - she bastes up on a pair of folding tables and uses lengths of elastic wrapped around the legs to give tension - she pins the elastic to the backing so the elastic is keeping things nice and taut.