One of the biggest problems that everyone faces in portraiture is making chins look good. Peter Hurley and other photographers tell you to direct portrait subjects to push their neck out just a bit. That works all the time, but another trick that also works well is making sure that the positioning of the chin is at the right elevation to begin with. This trick is a bit more complicated and requires you to “see light” so to speak.
Bringing the chin down more towards the chest squishes the area below it and therefore also makes a person look less flattering. Always have the subject bring their chins up just a bit. But to avoid having the scene look like they’ve got their nose in the air, have them stick their neck out a tad and place their face slightly off to the left or right.
Generally, I suggest that everyone faces the main light source in your scene if you’re working with off-camera lighting.