Some words about "more contrast" (which is needed).
If you want to have a real black in the image - and mostly you want - you have to give so much light that the film base gets this black. You cannot take lesser exposition. If you negative is underexposed the highlights are not white using "normal" contrast (whatever normal means).
If you raise the contrast the highlights get brighter. You and in an image which has sharply marked textures, what you may be not want always. But you have no other chance to get real black and real white form an underexposed image.
May be you can sacrifice the very deepest black and accept a very dark grey instead. May be you gain something by dodging and burning. But the main principle is: Underexposed negatives require much contrast in the positive process.