I myself just use safety pins to baste. I don't think you have to do both, just one or the other. Depending on how much excess batting and backing fabric you have I would run a basting stitch around the outside edge (you can do this with your machine) just to make sure all of the layers stay square to one another and one doesn't get pulled in or shifted from the amount of quilting you may be doing. The first quilt I made I didn't do that and at one point I noticed the backing fabric was no longer big enough! Hope this helps.