I'm on a marathon of watching various classes right now and one of the teachers suggested that you should quilt from the outside in. "Interesting," I thought, since I always go from the center out. She works on a grid, using SITD on the boarders first, then the rows of blocks, always working toward the center. She does spray baste and set it with the iron, so the sandwich is very secure. I haven't finished the video, but so far, it appears that she doesn't have any issues with is puddling up in teh center. The reasons she does this is 1) you don't have a lot of bulk in the harp of the machine until you get to the center. 2) You assured that your borders are nice and straight, with no wavy edges.
I haven't tried this method yet. I may try it on something small, like a pillow cover, or crib quilt and see how it works out.
~ Cindy