Wait around, a fight few battles. You don't really need to do a lot to refill draw points. Unless you're talking about physical draw points, then I dunno. But if you really want Ultimas, just put the Enc-None ablity on someone, (Diablos has it) and the Move-Find ability on someone. (Siren has it) After that, go and walk around the Islands Closest to Heaven and Hell whilst clicking 'X' repeatedly. The Island Closest to Hell has about five hidden Ultima points, and the Island Closest to Heaven has about three hidden Ultima points.

The Island Closest to Hell is your best bet on getting most of the high-level spells. You can find it on the west-most side of your map. It's a long deformed penninsula to the west of the Galabadia Missile Base. The Island Closest to Heaven has some good high level draw points, but not as much as Hell, although if you need Triples and Tornados, that's the Island to go to. You can find that one the east-most side of the map. It's a small island northeast of Esthar.