>>2956147i usually just use simple instructions like, Stand/sit there, look over at that, lean a bit back.
imo the photographers job is to get the best light, make sure it hits the face the right way, get the composition right, set the person youre photographing at ease, and let the subject project themselves the way they want to. Its important to talk to them all the time, lest they become self conscious.
this works for only a certain type of portraits ofc.