NM Camping

Kill beastment after beastmen in crowded newb areas where they constantly have to train monsters in and you can kill em all easy.

Quests, lots of em

Crafting(warning: Beginning crafters will have to sink at least 10K of gil before reaping profits.)

AH sell stacks of items

WHM? Teleport Services

Just keep farming, theres no quick way, every gil is hard earned.