Hi, this is my first post (besides the one in the intro forum)! I'm nearing the end of my first project - a triangular scarf. I was shown how to knit this scarf in a how-to workshop, and basically we are supposed knit increased rows, and bind off when we're out of yarn. My question is, how much yarn should I have available to bind off, relative to the width of the scarf?? I don't want to run out of yarn in the middle of my binding off!