I recommend heavily starching the backing fabric before layering. Also give the top several layers of spray starch before layering. Starch stabilizes the fabric so it is less likely to stretch and distort while you are machine quilting.
In my opinion, spray basting is one of the best ways to baste because it keeps all 3 layers in continuous contact. Pins, in contrast, create contact only every 4 inches or so.
It helps to use specialized gloves (machingers are a good brand). These give you a good grip of the fabric but still allow your hands to breathe and your fingers to feel.