I took a class in FMQ with Frieda Anderson whose best piece of advice was to sit on a pillow or two to ease your back and to be able to see what you are doing. It really works.
Quilting in sections works best for me if I want to FMQ. I have tried pre-printed backing for crib-sized quilts, and I also like the quilting on a roll for borders. Practice helps, as does a big glass of wine before starting!