Each drop removes the return path
Sunken Temple has stairs, levels, and drops with difficult return paths. Clear a floor before moving down. A player who jumps early can split the party across two floors with no easy route back.
Make the upper ring count
Kill all six troll minibosses on the upper ring before the main bosses. Their order does not matter. Skipping one makes Eranikus hit harder.
Keep melee spread around dragonkin. Their cleave can hit a stacked group.
Before Shade of Eranikus, assign a DPS to use a Healthstone or bandage the tank if the healer gets Deep Slept. Name the backup before the fight.
Fall damage kills more people here than the bosses. Never drop onto a level you have not cleared.
Agree on every floor
The layout can disorient the group. Agree on the next floor, regroup before the drop, and name the route before moving into the next pull.
Clear before every drop
Drop only onto a floor the group has cleared and agreed to enter.