This is for generic boss mob:

Boot or DK, depending on flank > Twin > Demo > Frac > DK > True > Snap > Boot > Twin > BfB/IR > Demo > Frac > ToD > DK > Twin > Snap > HF

Repeat using BfB/IR whenever they are up, unless deliberately saving for LB.
Frac/Demo every second rotation, reapply ToD every third.
If more than one MNK present, use Boot instead of DK if debuff will last another rotation. The DK debuff is universal and does not stack.

Bonus tips:
If you know you will have to run away or the mob will teleport, apply a fresh Demo/Frac/ToD.
Auto-attack is a big honkin' deal, so stay locked on and facing the target as much as possible--unlock and cut through mobs only when necessary to survive. Remember: the rear/flank bonus applies as soon as you use a skill, not after the damage appears.