As long as you are confident in your ability, preferably trying during daylight hours 1st to make sure you have a decent cast down when attempting at night.

2nd, string them about 12-14" apart, the more distance the more chance the 2nd fly has to "swing" more and therefore wack you in the head or back

3rd-crimp those barbs down, very impt as mentioned in the 2nd part

4-why 2 flies, well one works but 2 works better, Trout at night let their gaurd down more and it will not spook them as much as well as using 2-3X tippet since the shadows aren't as prolific than during the day when casting the line that wouls spook them.

5- Use coneheads and no split shot, cones will help sink (or use sinking line and no conehead) otherwise split shot will swing your line as well as slide down unexpectedly from time to time, if you must, tie a small knot on your tippet 16" above fly to keep from sliding

The guy in the picture with me is a good fisherman and never had tried the tandem till I told him to, well 1st cast and boom this big fish came out to get it....too funny!

Flies I was using was a size #4 Brown Barrs Slumpbuster
http://www.charliesflyboxinc.com/flybox ... arentID=37

Followed by a Olive Hot head #6 Leech pattern

Black is awesome to use at night most of the time but these were hot where I was at the other night...