Find a subject with a variety of planes to show differences in shadow and light. Keep the camera in a fixed position aimed horizontally at the subject. Place a plain background some distance behind.
Start with the light, fitted with its diffuser, at the same level as the subject and camera. Between shots, move it around the subject, so that you photograph this lit from the front, from the side, from behind and to one side, and from directly behind.
Then raise the light so that it down towards the subject at an angle of about 45 degrees.Again, move the light around between shots.
Finally, suspend the light overhead, pointing down, and take three pictures: directly overhead, from slightly in front, and from slightly behind.
What have I learned?
When the source of light is directly in front or above the subject, this produces very flat results, lacking in contrast. I prefer directional lighting because it shows the contours better. In this example the light is better when elevated otherwise the hollow opening just becomes a black hole.