This is definitely a whatever works/individual preference kind of thing. The basic question of midtone in both directions, dark to light or light to dark has been talked about a few times on CMON and for people who don't work the same way for any colour the decision on which method to use is generally based on how dark or light the colour is.
So I think one or two additional options in the poll would have gotten a few clicks as a paler skin could easily be approached differently to a very dark skin (where it would be more common to paint up from the darks).
I'd normally paint faces the way I do most mid-range colours which is midtone, some shadowing, then most or all of the highlighting, then the darkest shadows (excluding final tweaks). For darker skintones I might start from a middle shadow or even dark shadow colour and work up.
Einion