Avoid having skin tones show down low by wearing longer skirts, slacks, or darker hose.
Babies can be in white so we don't 'lose them'.
Simplicity is the essence of elegance. Here. the clothes, the hair, and the makeup present the subject powerfully.
Burgundy, blue, brown - they all allow the faces to be the primary visual element.
Formal clothes work exceptionally well.
Somewhat less-than-formal clothes work great if they are darker or even black.