My few quilts, mostly @ full size, have all been quilted on our regular machines (either the Singer 301A or Pfaff 1540). Worked fine for lines without a lot of close turns. On the last one I did outline some fairly complicated shapes so the quilt had to make @ 2 full turns for each one. I won't do that again LOL .
For the 301A, I thread-basted. For the Pfaff, I just used a few safety pins and I do mean a few; it has the dual feed so things don't shift much as you're sewing.
For relatively straight lines from one side or end of the quilt to the next, I roll or accordian-fold the excess. For more complicated things, I just sort of bunch it up so it's easier to manipulate on a turn.