Make SURE everyone is properly gemmed, reforged and enchanted.
Make SURE everyone has enough pots to pre-pot and pot again during Frenzy phase (<20%).
Use Hero/BL/TW at the start of the fight. Don't enter totems until it is over.
Don't always send 3 people down. Send only one dps and a healer when there's a low number of adds.
Make sure your healers refresh Spiritual Innervation on the DPS right before they leave the Spirit World.