My first instructor gave me the emergency procedure for engine out at night:

1. Perform a best glide descent until you think you are about 100' agl.
2.  Turn on the landing light.  
3.  If you don't like what you see, turn it back off.

I don't fly much at night any more for the same reason I get uncomfortable flying over mountains.  The notion that I can't land safely if the engine quits makes me nervous.  The fear is, however, irrational.  The chances of a well-maintained engine supplied with gasoline quitting in mid-cruise are documented to be very small.  If that were not so, none of us would fly at all.  The increase in accident rates for night flying (estimated by people like Richard Collins because there is no hard data on what percentage of GA flying occurs at night) tends to result from pilots not understanding the IFR-like nature of the exercise.

I think if you have and use IFR skills, keep your engine in good shape and don't run out of gas, flying at night is, objectively, almost as safe as flying during the day.  I don't think it matters much if you are over mountains (as long as you stay well above them which is easy to do with today's terrain programs) or in IMC, high or low.  Approaches are just as hard during the day as during the night.  But the irrational matters.  I fly for fun and it is not fun if I am nervous, whatever the reason.  I do miss night flying though.  It can be a wonderful experience.