Quote Originally Posted by rubah View Post
If you do level, then level your abilities in the cactuar desert (you have to walk a long way, but you can make it with the garden) so that you don't actually, you know, level up.
Level up your gf abilities so you can refine magic so you can junction it and kill tonberries 8)
The only dessert with cactuars in it are Cactuar Island and the other desert that I forgot the name (I think it starts with a K). That desert had abyss worms I believe. I personally got the Card Ability, turn non cactuar monsters into cards (Carding monsters do not give you EXP). My technique for encountering cactuars in that desert, always move near the darker dunes. Cactuars seem to appear in those specific areas only.

Use Demi/Diablos. Tonberries are weak against it. I got GF Tonberry at level of 20ish ( I believe 23).