I don't think I've ever did any grinding for this game... If you plan your jobs right, you can beat the game in the high 20's low 30's of levels.

Jobs are more important than levels in this game, so focus on ABP. If you want easy ABP, there is the cave near Jachol with the Skull Eaters. They give 5 ABP even if they run. Or you can learn Lv 5 Death and go to the basement of Val Castle and fight Objets d'art for 4 or 8 ABP per battle.