There's a lot to take note of here, and it would be best to view several times. If your image looks flat, there is always something to be done with lighting. It can manipulate how we perceive and object. Know to keep your images consistent, or risk losing your shot-to-shot relationships. Another video below is of an early Russian film experiment called 'The Kuleshov Effect'. Originally conducted by Lev Kuloshov, the video cuts between an actor and several other images. Take note of how the actor changes his expression for each image:
If you notice his facial changes for each image, you are mistaken. The twist of this particular experiment is to examine the effect each shot has on each other. The actor's face never changes, but when we see soup and then his face, we can tell that hunger is implied. When composing your images, think about the mood your lighting is creating and how it will be interpreted by the image before and how it will alter the audience's perspective to the image after it.