Either baste or pins. Both is over kill.
If basting - I like the Sharon Schambert method - kind of a zig zag instead of thread going in a straight line.
I find basting a pain if I'm machine quilting because if I don't pull the thread out as I go, it gets caught up in the foot, and if I sew over it, sometimes it's hard to get out.
If pinning, I just put one where ever there is an area more than 6", and not on a seam. Then whenever I get close, I just remove the pin.