There are a number of nice photos in this thread regardless of the techniques 🙂
When I first started out in film, I aimed for the high contrast look. Only to refine myself along the way after noting that in the shadows, lie wonderful tones. Like what another member said, you cant add what is not there. Retaining these shadows means you would have to shoot closer to box speed, rather than pushing.
The alternative is to meter a 400 film at (lets say) 1600. Develop at about 1250. You can do this for other ratings too.
The longer you develop a film, the higher the contrast.
The stronger your developer ratio, the faster your film 'reacts' and becomes dark.
Having said that, your exposure in the very beginning plays an important roll. The lighting available in the shot would play an important consideration if it turns out to be a high/low contrast scene too.
This is a great thread to recount the basics 🙂