The important factor when you shooting a portrait is light setting and distance between subjects and light. Also, the angel of light can affect shadow cast. In the broad lighting light comes from side of the visible ear and in short lighting light comes to the subject . In a classic basic portrait the main light reflect the subject . The fill light use to reflect the darker side of the subject’s face. The background light separates the subjects from the background.
This is my best photo from the class.