Best way to gain AP before final battle with Jecht

[crazybayman]

Uhm... don't do the above thing, at that point you become outrageously overpowered and just wipe the floor with him. It's what I did and I didn't have fun with him...
I'd say you should just wing it and see, he's not that hard.

That's the point isn't it?

The only way he's a challenge at all is if you just go fight him straight away.