The forest outside Mideel is the best overworld location to get AP. It's risk-free, but much more time-consuming than the North Crater.

If somebody is equipped with Mega-All, 4x-Cut, or Flash, the battles will almost be over before they begin.

I've done playthroughs with both strategies, and in the end, the North Crater is the way to go. As annoying as it is to get in and out of, you can rake in the AP. This is particularly useful in mastering KoTR.