First of i dont really care if this is a repost or not, i did a quick search and dint find it so here it goes ^^
What you need.
One player hat wants fast and nice XP.
One player that has this quest : Swift Action - Quest - World of Warcraft
What you simply do is even if you dont see each other bcus of different phasings, have the player without the quest follow the dot on the radar of the Player that has the Quest and is bombing the shit out of the Nagas, you wont get XP for the little ones that are one shotted but like 1,3k xp for every "bigger" naga that dies. If you aim properly you can net like 10k xp every 5 seconds.
Just remember to abandon the quest before it ends so you can repeat it over and over again ^^
Sorry for my (maybe?) difficult to understand english but its not my native language
If you have problems reproducing it fee free to ask and i will try to explain it more in detail.
(tested with several guild buddys now)