Collect the Manuscripts
Speaking of weapon upgrades, you’re going to want to play through the entire game again with a fine-toothed comb to collect every single manuscript available.
What are manuscripts, you ask? Well, they usually give you 10 SP each for weapon upgrades, but there are four of them which grant you extra Limit Break abilities –more on those later. You can get your first four manuscripts by purchasing them at the Moogle Emporium for five Moogle Medals each, but the rest need to be found or earned through quest completion.
Most of the manuscripts can only be obtained while playing on Hard Mode, and are gotten from beating bosses and completing side quests. These are pretty much essential for unlocking all the weapon upgrades, since farming SP the regular way is extremely slow.