I've been going to zones around demon invasions and dismounting to white attack mobs until some scrub from the opposite faction see's me "busy with a mob" then tries to fight me.
Then I camp them for 6-7 rez's in a row and /lol at least once per kill.
If you're going to try and gank someone who's pretty much helping the overall cause, and you manage to fail at that, you deserve to be laughed at.
Other then that, I don't use them in bgs, arenas. Just @ people who try to gank someone at a disadvantage in open world.