Fishing at nigth isn't any differnt than fishing during the day except you can't see!
Know the stream, know what positions you should be in, know where the fish are, big rocks, holes, be able to tie knots proficiently, never have slack in your line, and learn all back cast obsticles. Always make sure someone knows you'll be on the river or fish with a friend. Obviously, wear a head lamp and be prepared to eat and breathe in lots of bugs everytime you turn it on. I've gotten a few bigger fish lately and I wish I could get a picture of a fish illuminated by the small LED light with all the reflections and refractions disappatting into the dark water with a faint outline of the streambed underneath. Problem is the flash never truely allows you to catch the moment. If approaching an unfamilar stream at night, only go upstream and take it slow. Big patterns, like mouse patterns, work for bigger fish but so do smaller patterns. To fish the mouse pattern effectively, slap it as close to the bank or known holding water / structure then strip as fast as you can, pause and strip again. Jerk stripping is most effective but take practice on avoiding slack line.
I'm catching trout in streams right now that most people think won't be fishable again until it gets stocked. Why - I fish at night.
Tightlines,
Skiltonian