I have for 25 years printed my work on harder contrast papers to effect just the look you speak of, good rich contrast in the mid tones. I learned through trail and error that developing the neg to a lower contrast index was the best and easiest way to achieve the look you are after.
Masks, flashing, and extensive burning are a means to an end for negs already processed. The most effective way to control global contrast is at the time of development. Further, with today's multi contrast papers these lower contrast negs produce extraordinary prints with relatively little effort.
The best way to utilize today's multi contrast papers is to use only the highest and lowest contrast light or filter at your disposal. As Brian indicated, make initial determinations and print exposure for the mid tones with the highest contrast light and then bring the highlights into range with the lower contrast light.