Set up the greenscreen lights. These are powerful studio lights that are aimed only at the greenscreen and not the actors. There should be an equal number of lights, ideally four, on the top and bottom of both sides of the screen. This will eliminate shadows and evenly cast light over the greenscreen.
Use a light meter on the greenscreen to locate hot spots. Hot spots are areas with a higher amount of light than others. They can make editing greenscreen footage tricky. Adjust the lights until all the hot spots are gone and the greenscreen has a uniformed temperature.
Set up the soft lights. The soft lights are studio lights with a diffuser or lens. The soft lights should be positioned to face the actors. One light on each side should be enough. Position the actors in front of the camera, and adjust the intensity of the lights until the actors are properly lit.
Shoot the footage. Film several takes with different lighting options. This will allow the editor a choice for the best footage to work with.
Edit the greenscreen footage. Adjust the brightness and contrast of the subjects. Apply filters and other image enhancement plugins to correct the video until it blends with the background night footage.