Can you adjust the pressure on your presser foot? If so, adjust it so you have little or no pressure. Drop your feed dogs and you are ready to do free motion. Use whichever foot has the smoothest bottom.
Or I have used a decorative stitch to quilt also. You will want to pick one that continues to move forward and not go back & forth. That didn't make sense. (edit)
You don't want one that goes forward and backward.