If you are running traktor 2.6, I can tell you I abuse the hell out of iceverb, arctic wind, zzzurp or w/e (makes for a great metallic-electronic sound right at the end of a breakdown, or has an “arctic-lazer beam” sounding effect when set to 100 and is great in soft-bass lacking areas), delay, etc. For some of my transitions, I will use a loop + iceverb + delay to create a chill echo sound to transition into some songs (I love using it right before I play Fedde Le Grand’s Paradise remix). Also, I have been known to be a slicer/beatmash whore at times.
What I suggest doing is repeating 4-8 bars on a track (use a vocal track and a non vocal track) and exploring fx combinations/ play with your dry/wet settings and the fx setting while it is looping. This way, you get a good idea of exactly what the sound is like, whether you should have a dry/wet balance or set it all the way to the right, etc. You can add so much more to a song without cluttering it (like most inexperienced fx whores) when you utilize fx, and it adds a great performance aspect to your set. When I was at Cobalt playing with fx, I looked over to the sound guy and said “I have a bad habit of living on fx, sorry man” and he responded “no man, keep it up, you don’t hear it too often and I’m diggin’ your sound.”
I have a long ways to go before I can even pretend to be an fx master, but I’ve only gotten good feedback from incorporating correctly timed somewhat-atypical fx into my set.