1. The Sealed Castle of Kozer can be visited just after Exdeath's barrier knocks you off the Big Bridge and you've been to Rugor. Make sure one of your guys has Monster Trainer built up. Fight the ShieldDrgn's and Control them. You won't be able to kill them otherwise at your current strength. After Controlling them, their Flame does 4999 damage to themselves, and then can stand 20,000 damage. So one of your attacks and 4 Flames will kill them. They hand out ABP and EXP by the bucketful. I was seriously able to go from level 20 to like level 27.

2. The Statues in Bal Castle can be killed by Softs or L.5 Doom. Just learn L.5 Doom from the Ancient Library and have your fastest person equipped with "!Blue". L.5 Doom will reap their souls, and they offer 4 ABP for groups of 2 and 8 ABP for groups of 5. If you're out of MP in the middle of a battle with them, GP Toss will work. They give you plenty of gold, so don't worry about the occasional money-waste. Frequently go to the Inn and Item Shop. If you have enough money, buy 99 Cottages and just use the Save Point right before their little section. Believe me, I was able to master like 3 or 4 Jobs before fighting Exdeath. Very cool. Note: I didn't find out this trick, but I developed the trick to a big extent.

3. Fight the monsters in Exdeath's final dungeon. They offer 29-30 ABP and tons of experience, and you sometimes fight Movers. Movers give you 199 ABP and 1,999,999 GP. You can leave the Cleft of Dimension and buy tons of rings and other stuff.

If you don't like building up, you're not alone. But believe me, just getting 6 or 7 levels lets you win easily.