I do all the emissaries or at least all the emissaries where the quest selection doesn't look intimidating and mostly I do it every 3rd day.

I normally 8 box these days, first team is fury warrior, disc priest, resto druid and 5 bm hunters
Second team is 2 boomkins, ret pally, havoc dh, ele shaman, frost mage, shadow priest, frost dk. Basically as diverse a team as I could possibly make using the toons that I already had leveled.

Needless to say the first team is stronger, second team dies a little bit when doing the 8.3 content but is stronger in pvp (since melee is easier to face targets). All that to say you can pretty much use whatever teams you like.