I didn't do much training during the course of the game. I know I did stop for awhile and fought along the Rinaul Coast with Squall and Quistis before heading to the Fire Cavern. Just fighting one random battle after another, seeing the same enemies over and over again, it gets very tiring. I'm the type that wants to move on with the story and see what happens next. Well, when I did do some major training it was on the Islands Closest to Heaven/ Hell. Just bring along the lovely Quistis and have her perform Degenerator over and over again. Keep her in the yellow. She'll get taken out, every now and then, so use Life to bring her back. You'll level up, quite nicely, in no time. Sure, it's the lazy persons way to level but hah, it works.

I just make sure I have plenty of Auras when goign to the island closest to Hell (I rarely go to the island closest to heaven due to the massive amounts of Malboros) and I just dominate with Squall.

Leveling up is always time consuming, though, because I stay below level 30 until I reach Ultimecia's castle due to the level fluctuations of creaters up to there, and the fact that you can max out your stats with junctions around level 20.

Of course, its sad when you beat Ultima Weapon in two moves, then get your ass handed to you by Omega, lol... I still can't beat Omega without obtaining Laguna's card and modding it into 10 Holy Wars.

Laguna's in the only character card I mod... but there are some GF cards that I mod, as well. And I mod every non rare card once I have more than 5 rare ones... that way you always get good cards when playing Random.