I'm a very humble printer, but what I've learned -from others and from my experience- is that there is no way to get a "tonally pleasing" print from an underexposed neg. If the negative has wide areas with very low -or virtually null- density, there is no way you can get tones in there. You can just make it a bit brighter than black.
My experience tells me that, in such cases, the best strategy is to live with the black areas. Don't be tempted to lower the contrast to bring those tones back in, it will not work. Just leave them be and adjust your exposure and contrast for the readable densities: depending on the composition, you may as well obtain a communicating print.
My two pennies.