This trick is useful to level up much needed spells such as Protect, Cure, and Shell. Go to a local residential area and stand directly outside your Mog House. Cast the desired spell on yourself until you run out of MP. You can also cast it on other players running in and out of their Mog House. Once you have run out of MP, run into your Mog House, replenish it, exit, and repeat. This saves a large amount of time from having to heal after casting. You can level up magic by casting the spell on yourself, despite if you already have the enhancement on yourself or have 100% HP. Keep casting and it will level up.