- Valefor, Yuna's first Aeon, has two Overdrives. The second Overdrive, Energy Blast, can be unlocked in Besaid Village after speaking to a little girl and her dog.
- When doing the Cloister of Trials located in each temple you visit while progressing the story, take the time to find and use the Destruction Sphere located in each and get the appropriate treasure to unlock a potential late-game summon.
- A character only gains experience if they take an action in battle, even it's just to defend. Try to make active use of everyone if you don't want anyone to fall behind.
- Tidus' Overdrives unlock based on times used. Wakka's unlock from winning Blitzball Tournaments. Kihmari must use his "Lancet" skill to unlock monster skills for his Overdrive. Auron's unlock from collecting Jecht Spheres. The rest do not require unlocking tiers.
- Rikku's Mix Overdrive is gamebreakingly powerful if you look up the right combinations, but just experimenting is likely to be more fun and balanced.
- Blitzball can be cheesed by getting in the lead and then hiding behind your goalie until the timer runs out.
- When you summon the aeon Yojimbo, paying at least 1025 gil each time will increase his odds of using a powerful attack, particularly the boss-slaying Zanmato.