Whenever possible, I try to create some interesting and dramatic lighting on the set: having no professional lightspots, I unplug all the lamps in my apartment to help illuminate the scene and give it a nice 3 point lighting. But sometimes, I find myself with utterly flatly lit footage, like in the car scene here (cramming all the lights in my Honda and still getting the fucking green screen lit evenly against the window frame sure didn't help).
This is when composting comes in handy. And, Jesus Christ, bless Adobe for giving us After Effects! I go to town on color correction, throw in a couple of virtual lights (well, in this case, more than a couple...) and the scene looks much better already. I find that I can really enhance the staging idea of a scene by shaping the light and shadow areas on screen, directing the eye exactly where I want it to look.
If done right, the stakes of the scene are instantly readable to the audience. In this scene, the groceries in the bag only provide the context, the real interest is the fish and the sunset on the sea it sees through the window, the sea where it belongs but will never return to....