Teeler,
It is very important to vary your activity to avoid the issues with neck and back pain. All o our bodies have different tolerance levels and we need to work with it. I try not to FMQ on a large project for more than an hour at a time. I like to STID around every square and around each border so the quilt is stable. I like to use 60 wt thread on the top and whatever thread I use for the whole project in the bobbin. After stabliizing I can quilt wherever I want. As a result I quilt from the outside to the center. As soon as I have the border quilted I put on the binding-this removes a lot of bulk and is easier to handle. I like to hand stitch the binding to the back and do a little bit at a time. Usually my binding is finished before the quilting is finished. I always have more than one project going so I can use my body in different ways through the day. I set goals so a project needing to be quilted gets done. I'm doing an intricate design in 48 squares now-I do 2 squares each day-and them move on.