Light direction and strength can have a major impact on the mood of a portrait. You can use light direction and light quality to change the look of your portraits. Pay attention to what direction the light is hitting your subject and experiement to see what you can do creatively to make the light work better for you. Side lighting is of course the most commong and often the most redeming, but other directions can be interesting too.
Look through the images to the right and see if you can tell: