You've probably already thought of using welding goggles to darken the range in the safety of daylight.
Much easier to watch and correct than trying to do it in actual darkness.
Place targets in obscure spots on the range, like behind stuff, to emphasis accuracy of both light and gun.
Use enough no shoots on the courses of fire to require good target ID.
Add a small amount of light on the range to cause outlines and shadows, but not allow positive target ID.
Strobes add some confusion of light, requiring good flashlight techniques to find targets, that will seem to appear and disappear.
If possible, break up the range into small areas, each with targets and props.
Surprise targets are always a heart stopper in the dark.
If this will be at an indoor range, make sure all the targets align with the backstop.
In the dark, it's so easy to hit the walls.
Hope this helps some.
