Placing Bulwark on an ally under attack is a good way to regain Health.
Righteous Gust can be useful for charging opponents or escaping pursuers.
You can significantly increase the damage potential of Idol of Durand by using it when multiple enemies are close.
Avoid attacking Galio's allies while they are Bulwarked, since your attacks will be less effective and will heal Galio.
Avoid bunching up with allies when Galio is nearby.
Interrupting Galio while he channels Idol of Durand will free any allies he's taunting.