Battle Shout

Battle Shout is the first shout a warrior receives, learned at level 20. Costs no Rage while providing 20 Rage. As a shout buff, it affects all party members in its range, increasing Strength and Agility.

Improvements
Booming Voice: Reduces the cooldown of your Battle Shout and Commanding Shout by 15/30 sec and causes those abilities to generate 5/10 additional Rage.

Glyph of Battle: Increases the duration by 2 min and area of effect by 50% of your Battle Shout.

Tips and tactics
There is little reason not to keep this (or Commanding Shout) active at all times. However, as the rage generated will quickly decay when out of combat (and as both shouts have a default cooldown of 1 minute) players may prefer to wait until immediately before commencing combat before refreshing them, ensuring that none of the rage is wasted. If a longer duration buff exists (see notes) then shouts should still be used for the 20 rage.

Combined with the talent Booming Voice (which is early enough in the Fury tree that any warrior can obtain it) this ability becomes a very potent rage generator. Without the talent, the shout has a 1 minute cooldown and generates 20 rage (20 rage per minute). With the talent, the shout has a 30 second cooldown and generates 30 rage (60 rage per minute). Combined with Execute, Heroic Strike or Cleave, this can be a DPS increase.