This is what i did

At any area i killed every monster untill there is left only one.So i had beowulf cast chicken over and over on the monster until its brave reached 0.then i put it to sleep.I then had a character steal gil from it or use accumulate(2nd ability slot).I also had Ramza use yell on the character i wanted to Lv up or gain Jp.Also Gained Jp up Makes it easier.