Faster Level Up
After you get to Zellis, raise your character up to level 16. Follow the mountains west of Zellis until you get to where the mountains are right beside water. Stay at the very bottom part. You get to fight Brains, B. Demons, and other enemies near Pell. I got my character up to level 18 in about a half an hour (it helps if you have Lux).
If you are Lux, get a partner that is good with Magic (I would pick Esuna and keep using Ice and Ice 2). When you get low on mp and/or hp, go back to Zellis and heal yourself. Keep doing this until your at level 20-22. Then go to Melenam and beat Red Pison.