On SCH or WHM? Because they are very different strategies. On WHM you need to use Esuna on anyone who is poisoned to save MP, and make healing much easier. On SCH it's much much harder because you don't have anything to remove poison, you need to make sure your parties know what they are doing, and make very good use of aetherflow to restore MP, Eos is also a valuable asset, if she dies swiftcast summon her asap (if you have leveled THM).