I have incandescent lights in all my buildings and use a rheostat to dim them so they have a nice look. Even though I have fluorescent lighting now in the train room, I have also installed a few incandescents (also on a dimmer switch) so night operations can be carried out (not in complete darkness, of course...). Night operations add a whole other dimension to running trains.
I also tried lighting a couple of my cabooses but the constant flickering killed the effect. I'll try using a 9v. battery & a microswitch later on for these.