The only thing I can add is...if you discover you have loops on the underneath it's because you are moving your quilt either slower or faster than your sewing speed. You need to be moving your quilt at the same pace as your machine speed to get even stitches on both sides. It's really not as hard as it sounds, and, like everyone says, practice practice.
Also, this gal has created a neat sit down free motion quilting setup for use with a domestic machine. It's really cheap to put together and looks like it would make FMQ easier. There's a part 1 and a part 2 to this process.
http://www.youtube.com/watch?v=g14go...feature=fvwrel