Some of the best portraits are those taken simple lighting. You don’t need to get too complex with all your lights and you don’t need fantastic, exotic backgrounds either. The focus of the portrait is on the subject, not the background and surroundings. Yes, an editorial or other styles of portraits the background will help tell the story, but a pure portrait will have a story told by the subject. Their eyes, their emotions and expressions will be compelling enough to carry the portrait. Have a look at Wikipedia’s definition of a portrait.
As a professional portrait photographer, it is your job to find the correct lighting to bring out your subject’s personality. The same “cookie cutter” lighting does not work with every subject. BE careful not to rest thinking you know a lighting setup and that will carry you through your journey as a photographer. Knowing the lighting and shadow patterns is important, but knowing how to apply them takes time and experience and an attention to detail. The great photographers on this planet make it look easy, but they know what light looks best for their client. Face shape, skin tones, eyes, ears, part of the hair and all the facial features are carefully analyzed and a decision is then made as to the best lighting for the mood of the shot is required.
So, remember to take a few minutes and look at any photographs of your client or sit before your shoot and take a few moments to learn a bit about your client and also look at the features your client has and figure out what you would like to highlight and figure the appropriate lighting from there.