Helicopter landing sites must be checked out in daylight on the same day as they are to be used at night. Preflight checks should allow for night flying—carry a torch, and 2 landing lights are preferred. Permission to enter the rotor disc is given by flashing landing lights.
Hovertaxi higher and slower than by day, making no sideways or backwards movements. Great care should be exercised in pointing the Schermuly flares to a safe place at all times (which is admittedly a bit difficult when they're fitted and the fuelling truck pulls up right alongside them). The flares should not be armed at this stage, but at the holding point immediately before take-off and disarmed at the same place after final approach. They should also be disarmed after reaching cruising altitude.
The maximum useful height for discharging a flare is around 1800 feet. Its burn time is 80 seconds, during which time it will fall about 1500 feet. Therefore, having established autorotation after an engine failure at night, the first flare should be discharged immediately, or on passing through 1800 feet, whichever is later. Don't bother doing it before this, as they will be useless. Due to the way the switches work, and depending on the height at which your engine stops, you may not be able to set off more than one flare before landing, but, if possible, the second should be discharged between 800-1000 feet agl.