question to artists, when u shade dark skin, do u focus more on the highlights or shadows? which do you work on first?

i want to improve on shading dark skin because zabella has dark skin, but i've approached it the same way i would w lighter skin which probably isn't the best.

i had this thought after seeing this amazing piece and i wondered if the artist started out with the highlight shade as the base or the shadow as the base color. https://twitter.com/stephpeppery/status/1308227415496298496?s=20

i always start out with a base color and focus more on the shadows than highlights. but i once saw an artist i follow (i forgot which one i'm sorry ;w;) say that the magic of dark skin is in the highlights, while for light skin it's in the shadows. what do you all think?