Remember at 66 shaman get Earth Elemental Totem, using 1-5 of them generally gives you enough time to dps the boss down. The only issue is learning bosses, if you wipe and don't have enough Totems left then you will have to wait 20 minutes. It only ever was an issue from the first boss of Sethekk, now I do it with 2 Earth and 2 Fire and its fine even if I somehow wipe.