Most negatives which I have gotten to enlarge from others were underexposed and over developed. For me underexposed means simply put, using the wrong ISO rating. Of course metering etc. comes into that. It also relates to how the manufacturer gets this ISO rating and what it means. As I understand it and I may be wrong here but the rating correlates to a contrast of 1,5 am i wrong here? or me that is an overcast day in winter. Not a sunny day when many people take their cameras and run on the streets.
I aggre to the comments of Michael about local contrast. That is too often ignored. One shouldn't just totally fit the development to fit to the paper contrast. If the scene is contrasty it should be kept that way. Here we come to dodging and burning.
I would say that if one tests his stuff one will realize after awhile and handle accordingly. It is a matter of feeling and grasping what to do and that takes time.
To go into the finer details of all this would take up so much space in a book so it isn't really mentioned.
Yes in the good old days when the matterials were not that good as today the control of the situation was more important than today. With the long contrast range of today we can just record the situation better, but we need to get that exposure right and bend it in the direction we want and need.