My tips for dps (my opinion and nothing more)...
1) Let the Tank pull and wait a second or two.
2) Make sure you are focusing the Tanks initial target or if using marks...make sure you are attacking the correct target.
3) Refrain from doing burst damage at the start of the fight.
4) If you do get aggro then stop attacking and try not to run away from the Tank (something I find myself doing sometimes...angry mobs are scary)

Also personally...I think it's ok for dps to grab aggro off the healer, but I'd stop attacking the mob after getting aggro so it's easier for the Tank to take it from you.