Iffum I were stippling, I would start in the middle and work my way out. If I were doing free motion to a pattern, I would stabilize the quilt by sewing along block lines in the ditch then work on whatever block took my fancy at that time. The ditch will keep you from bunching up long pieces of un-quilted fabric.
I plan on doing diamond pattern all over the top on this present quilt (a quilt meant as a present). I will first stabilize on the block edges with dissolving thread, then start in the middle with the diamond straight lines, a walking foot on the mighty Bernina.
I don't anticipate any issues with this scheme.
Good luck,
tim in san jose