It depends on a lot of things, for me that includes the size of the project and the style and complexity of what I am quilting. Free motion can be anything from a large meander to very tight and complex designs.
If I can, I like to do some sort of stabilizing or grid to start with. I was recently given a quilt with a large fancy star shape, current thought is that I would indeed stitch in the ditch around the star points to stabilize and then fill in the sections with free motion.
Even on a small project that is sprayed down nicely, I'll put in a few stabilizing safety pins until I get some stitching in. Just a few. So, if I'm starting in the middle, no pins there but the corners and edges are held down.