Quick leveling tips for characters?

[Lone Wolf Leonhart]

I've got several people in their 30's and would ideally like to make it to 50's or 60's.

I know about the trick where you go to the training room, leave someone there, and set your system's clock forward several days. But I was hoping to find tips for heavy grinding spots or areas that have enemies with a high respawn level. Something like that.

[Saber]

Ok what you want to do is level up until chapter 7 where you can get to Shakara. From there is some good enemies (flans and bombs) + kind of a mini boss in the forests named Marduk. When you get your players level 30-40 it might be an good idea to continue into the game to new game plus. After that complete the game and repeat on a higher difficulty. After that you can just play again to Shakara where the best exp and areas are open.