Spots to 3 Barrel, and spots to call the 3 Barrel

Lets see 2 good spots for a 3 barrel:

That means betting the turn you have almost always have to bet the river, depending of the metagame and if the board pares.

The same aply when to call the barrels, if you chose to call the turn, you must call the river.
This a standard rule that also depending of the metagame, and some no brick cards on the river.