1) Start with Mako Might/Dr. Mog's Teachings
2) Equip Acestriker/Battleforged and spam white magic (either Diaga/Holy against Holy-weak enemies, or Cure spells; the higher the level, the better, since higher level abilities give more gauge)
3) Equip Gathering Storm and spam white magic
Note that the bolded are the Big Five™ Record Materias, the RMs that 99% of your team builds will have at least 2-4 of.