SAMPLE FRUIT BOWL LIGHTING BREAK DOWN
Keylight: This is the main source of illumination for the scene.
Fill Lights: Used to help illuminate all the dark areas created by the key light. The fill lights for this scene are actually fairly dark because I wanted to keep the shadows from the key light dark and moody.
Rim Lights: All my rim lights in this scene has a blue tint to them. I'm trying to imitate the color of the background cloth because real light rays would bounce some of those colors onto the foreground objects.
Bounce Lights: My bounce lights are only affecting the plate because I wanted to bring that out of the shadows on the lower left. I didn't use any bounce lights on the fruits because I wanted to make them feel more grounded to their shadows.
Background Fill Lights: I wanted to bring the background out a bit more so I added some fill lights that were only linked to the background object.
All Lights on a Grayscale Shader
Final render with all lights and shaders turned on: