The figure 8 follow through, or figure 8 retraced, however you care to call it, is a great knot for a lot of places. But I make it a whole lot easier than tying a single and then keeping track of everything while I thread it and retrace it back through the original knot. Start by threading your line through the hook eye and doubling it back along the tippet. Now holding both lines as one, simply tie a single figure 8 as if your fly was the end of the line. The lines stay together thoughout the knot and it's a whole lot easier to keep track of.