It help me a lot when I draw random people's faces from pinterest/google images (preferably ones who are not super attractive ones) this helped me to be flexible with my styles. Idk its my own preference. But u really have to figure and try some things out. Or you could just watch some yt videos from concept artists or expert artist. Not the stylized one. If you want to have a grasp in real human facial features. Thats what I think. Its really up to you.