This is a simple exploit that I encountered in Heroic Ramparts.
On the last dragon boss there are two guards before him.
Kill one of the guards, pull the other one back to the beginning of the bridge and kill. The two guards will reset and the humanoid boss will not spawn. If you want him to spawn then don't pull the last guard.
What could you do with this exploit?
Easy 15 reputation... not much but its 30 rep combined with both guards and you can rinse and repeat. They respawn about 10 seconds after you kill the last guard.
Enjoy.