I knit socks on DPNs, one at a time, like they did in the olden days. I don't usually suffer from second-sock syndrome, but it is sometimes a loooong time (months, say) between finishing the first sock and finishing the second. And so I keep good notes on shaping at the toe and the heel, and on any patterning, but often my bind-off edges don't match. I use Jeny's Surprisingly Stretchy Bind-Off, which works beautifully, but somehow my tension is often not the same between the two socks, or I manage to wrap the yarn differently -- in any case, the bind-off edges don't always match between the two socks.
So I started putting the first sock on scrap yarn when I get to the part when it's time to bind off, and then I cut more than enough of a tail to finish the bind-off edge and weave in. Then, when the second sock gets to the same point, I do the bind-off, then immediately repeat the same process on the first sock that I finished. That way, I get matching cuff edges!