There is no grinding in these games. There is a finite amount of exp in the world. Enemies do not respawn. Most battles are won entirely with placing your team strategically around the field (never lump them all together to prevent AoE spell targets or being in the middle of battle field effects)
Take full advantage of the environment. If your enemy is wet or standing in a puddle of water or blood, using a lightning spell or using cold and freeze them. Use a poison cloud (highly flammable) or Geomancy spell covering the enemy in Oil and ignite it with a fire spell for explosive damage. You can also use objects on the field fill a barrel with heavy objects use telekinesis and drop the barrel on the enemy. This also applies with high strength characters that can throw the barrel instead. Works on elemental barrels containing water, oil, or poison too (they have the same elemental trigger effects listed above too)
Think outside the box. IF you think you can try something, chances are it probably will work. Slugging back and forth like a mindless traditional RPG leading into drawn out conflicts will not help you in this game.