Love the comment from other pinner, "How to use a double needle tutorial.shut up! This is amazing. I learn new sewing stuff all the time!" The other thing I didn't know is the double needle seam stretches.
Needles for free motion quilting: Topstitch needles ( or They have a large eye, meaning less chances for the thread to break. Image shows the difference between an universal needle, a quilting needle (sharp point) and a topstitch needle (big eye).