what is the strategy for 4 shaman for pvp?

fire: 1 wrath, drop 3 nova or start with 3 searing and another hotkey for nova?
water : 1 cleanse and 3 healing?
air : 1 windfury 3 grounding?
earth : 1 bind, 1 stone, 1 tremor and 1 claw?

Please share what should be the correct way..