So, im sure you have all had problems with a ton of people trying to kill named mobs for quests. On my server, people would crowd the spot where the mob spawned and just spam AOE attacks. It was near impossible to get the first hit.
If you use a macro, and an auto clicker (or just spam click manually), you can always get the first hit!
Macro:
#showtooltip Sinister Strike
/console targetNearestDistance 10.000000
/targetenemy [noharm][dead]
/console targetNearestDistance 41.000000
/cast [harm,nodead] Sinister Strike
Obviously if you not a rogue, replace sinister strike with a different instant attack. (Arcane Shot, Earth Shock, Moon Fire, Fire Blast, Mortal Strike, etc etc etc) Now put this macro on your bar, and fire up your favorite auto clicker. (I set mine to click on every 1/100 seconds.) Or just spam the button when you think the mob is going to spawn. The macro will constantly try to find a new target, and the hit it with the instant attack. Just make sure your facing the direction of where the mob will spawn.