how i do it (and it seems to work fairly well), and assuming you have 3 mobs A, B and C

1. Mark the main target (A) you want everyone to attack (so people dont start attacking everything and make aggro management even worse) with /enemysign
2. Shield Lob > A
3. Get in range with all the mobs A, B and C
4. 2x Flashes and make sure all A, B and C are hit
5. Complete a full Fast Blade > Savage Blade (and later > Rage of Halone) combo on the main target, A
6. Use the highest enmity attack you have (either Savage Blade or Rage of Halone) on B, then use it again on C
7. Go back to A and use the full set of combo again

things may vary sometimes but this usually works.