Depends on the quilt. If its a gift, I generally do a backstitch front and at the end of the thread, but for a quilt to be shown I always knot and bury the thread

I always bury my threads, don't knot them, just weave around in the batting a bit with the needle before I pull them through. I do most of it as I go along, then go back and catch any that I missed when it's finished. I don't like the thread build-up either from backstitching or from starting off with tiny little stitches. I don't care for the way it looks or the way it feels.