In most of the places I’ve lived, I’ve had hot water fixtures that gradually started dripping again no matter how tightly I turned them off—I figured the problem was that the valves were weakened from being overtightened, and I was faced with the tradeoff of continuing to overtighten them and gradually make the problem worse, or undertighten them and deal with the drip.

But recently I realized the real issue was that the valves were shrinking after they cooled off, causing the seal to loosen. So I changed my routine: after using the hot water, I'll shut the water off lightly, then wait 30 minutes for the valve to cool and tighten it again.