Needles are an individual preference. I have had classes where the instructor had us use size 70 needles for free motion quilting and the next instructor had us use size 90. If you have a tendency to break your needle as I did at the beginning, start with a 90 for FMQ and work your way down as you get experience. The smaller the needle, the smaller the hole. For piecing I use 70, 75 or 80 sharp. Whatever I have on hand.