I got simple solution for you.
Get
Trick or Treat, then actually start using ToT.
I'm using it on CD (well, almost), and rarely seen less than 100k bonus damage (single target without any additional buffs or debuffs) during bossfight.
Taking into account that 25% of my tricks (plus one more at pull) are energy free (ToT macro'ed to mutilate from stealth) raid getting 400k additional damage every 2 min with the cost of 45 energy.
During AoE situations, burst phases or during some specific bossfights (Elegon, Garalon, Wind Lord, Amber shaper p3, Protectors, Lei Shi for example) you gonna see insane numbers of bonus damage dealt with your ToT.
On our 1st Elegon HC kill prot warrior did more than 1 million bonus damage with it during execute phase (before vengeance was capped).