It depends what kind of negative size you are using. With 35mm, adjusting contrast on the negative will mean more visible grain and blocked highlights. On the other hand, large format people do it all the time, because they enlarge less and/or contact print. For 120, it depends on the film, the scene, your taste, etc. Some people do it, some people don't.
I shoot mainly 35mm, so when I need a higher contrast, I simply switch paper grades.
However, if you want a high contrast photo, best to start with a high contrast scene:
(there was a url link here which no longer exists)
In that photo, I metered for the highlights. Because the window was the only source of light, and the room was dark, the subject's left side fell into near black.
If I had metered instead the shadow part, I could have raised it to a normal tonality, and got some blown highlights on the other side, which is a completely different photo.
That's one kind of situation where using a reflected light meter is really useful.