For my money it is all about awereness of the clues leading up to engine failure. You don't always get advance warning but often there are tell tale signs. At night I pay far more attention to these and also ensure that I have checked everything throughly. There is an increased risk but flying over a built up area carries an increased risk as does flying over mountains, and flying in IMC.....
Hell flying at all is probably the first mistake!.
When I took my heli course I asked about the need for a flare as night equipment and was re-assured that this was to let off at the last moment so that you could see the cause of your death just before it happened. Felt much better after that.
Fly higher, enhance situational awareness, and do the checks more frequently is the best advice I can offer.