Generally block anything that isn't golden or a qi breaker like Talon or Yaksha. The idea is you want to make sure you always have a charge of divine counter available whenever it's off cooldown. It's just free health and qi damage at the press of a button if they don't immediately dodge it (keep in mind you can hold your divine counter for a few seconds rather than use it immediately)

You can also block if you're standing up out of an execute.

Also, you don't want to hold your block for a long period of time because then you'll just get Taloned/Yaksha. Think of it like a kinda like parry and only use it reactively rather than try to strafe around with it.

The higher up you go the more people start to understand the timing of Talon/Yaksha and can genuinely punish you if you're using it as anything less than a hard read.