In Position as the Player Who Called Preflop

There is more incentive to call (rather than raise) with nut flush draws when you are in position. That’s not to say you should never raise them, but leaning towards calling is typically the best approach.

Out-of-Position as the Player Who Called Preflop

Because of your reduced ability to reach showdown, you have more incentive to check-raise nut flush draws when out-of-position. Lower flush draws should be called more often.

In Position as the Player Who Raised Preflop

When you have a big range advantage, the optimal way to play is aggressively.

Out-of-Position as the Player Who Raised Preflop

When the board hits their range hard, you have to play extremely defensively. That includes checking with most or all of your nut flush draws.

When the board is better for your range, you can do a lot more betting. Most of your nut flush draws should be in your betting range on such flops.