The key is that the sandwich has to be nice and taut. I usually tape the backing down (nice and taut) and then flatten the batting and then flatten the top. I smooth things out from the center to the edges before I pin about hand-width apart.
I roll the top from each side to the center and SID each line first in one direction then turn the quilt 180degrees and SID the other direction.
Then I reroll to the other side and do the perpendicular lines. The better the prep work is, the less puckers I have (I also use a walking foot).