Every so often I love to underexpose black and white film on purpose. There is something fabulous and eerie about a wide open composition underexposed by about two, maybe even three stops.
The result is typically a sort of murky mass of dark gray and black with only the absolute highlights of a scene transitioning into white. It may be a little gimmicky in some respects, but it matches the mood of the overcast Pacific Northwest really well not to mention bringing out a whole lot of punchy film grain.
If you are lucky enough to have a camera with an exposure compensation dial I will usually set it to negative two EV. My hand held light meter also has a way to automatically dial in up to three stops of either over or under exposure. Closing down a lens a couple of stops isn't a difficult thing to do however so its not like the technique is super complicated. You just have to be willing to take a chance that you'll like the outcome.