Spam the Stealth Skill
In Dragon Age: Inquisition, rogues can make themselves invisible anytime the skill’s cooldown isn’t active. Now, as said before, this can always be used to avoid being attacked when an enemy decides to focus on your character. Nonetheless, there are several other ways in which Stealth can be used to the rogue’s advantage.
First of all, attacking while being hidden will increase the damage done by 50%. Moreover, Stealth can be used as a combat beginner, allowing your character to move deep (or even behind) enemy lines or a beneficial position before it all begins.
In the same way, you can always activate Stealth after a kill is done to approach your next target unseen. This will not only avoid a lot of damage, but buy some time until skill cooldowns are over.
Finally, Stealth can also be used to approach and revive felled companions without generating threat.