Everytime I have done a nightime image it ends up too dark.

Like these ones

http://photoshopcontest.com/view-entry/179906/red-light-bird.html

http://photoshopcontest.com/view-entry/179652/displaced.html

http://photoshopcontest.com/view-entry/180228/deaths-hand.html

You have to draw in the night light as a colour, night light is commonly blue, so why not cheer it up a bit with some upbeat music and remember, if your picture looks black, it's probably Doom 3.

maybe punch the contrast a bit, just an idea