Use the following trick to enter Perfect mode very quickly without taking any damage. When surrounded by a group of enemies, rapidly press [Parry] to block all incoming attacks. As you block, your special meter rises very quickly, bringing
you to Perfect mode. You can now quickly take out all nearby enemies while racking up the Perfects. This is very useful in Pelennor Fields.

An easy way to get to Perfect mode is to use Orc Bane, Bane Of Saruman, or Warrior Bane.

To get perfect mode, use Orc Hewer many times. You will soon enter Perfect mode.