I used artificial light for my portrait pictures.  I set up a key light, a fill light, and a back light.  I moved the lights around while taking the pictures.  I also turned the back light off and on.  I tried to work with the shadows on the face.  I set the ISO to 800 and the white balance to Tungusten bulb.  I tried to take pictures at different angles.  I did not use a flash.