¤ Secrets

World Map Locations: Use these following coordinates to locate the secret areas for great items!

Baaj Temple -- X:14 Y:60 (find Lulu's Onion Knight and Anima here)
Sanubia Desert: X:15 Y:41 (find Tidus's Ascalon)
Omega Ruins: X:74 Y:36 (battle Ultima Weapon, steal items, and find spheres)
Besaid Falls: X:31 Y:73 (find Kihmari's Dragoon Lance)
Mi-I'hen Ruins: X:34 Y:58 (find Rikku's Sonar here)
Battle Site: X:42 Y:57 (find Lulu's Phantom Bangle here)

Airship Passwords: In the input section, type the following words in exactly how they are put here (all caps) to find great items.

GODHAND: Obtain Rikku's ultimate weapon.
VICTORIOUS: Obtain a powerful armor for Rikku.
MURASAME: Powerful sword for Auron.

Jecht Sphere Locations: Here are the locations for the Jecht spheres for Auron's overdrives.

Jecht Sphere: Macalania Forest (after Spherimorph fight)
Jecht Sphere: Besaid Village (next to temple)
Jecht Sphere: S.S. Liki (on the bridge in Besaid)
Jecht Sphere: Luca Stadium (basement level A)
Jecht Sphere: Mi-ihen Highroad (southern Old Road)
Auron's Sphere: Mushroom Rock Road (cliff)
Jecht Sphere: Moonflow (South Wharf)
Jecht Sphere: Thunder Plains (southern part)
Jecht Sphere: Macalania Woods (southern area)
Braska's Sphere: Mt. Gagazet (Mountain Trail)

¤ Tips

Classic RPG'ing

Always be sure that you have a fairly good amount of items, incase of an status effect during battle, or near fatal attacks. Besides, it requires lots of items to give your weapons and armor great abilities in Customizing them.

Always save. Whenever you see a save sphere, it is 80% of the time there for a reason. There may be a boss up ahead, or a long trail of hard enemies. You never know. Also, you fully restore the HP and MP of all your characters, including Aeons.

When in battle, you should use everyone. Switch between characters and have them just do random things if you know they will kill the enemy. Have them use specials, or skills, or even items. Everyone needs AP to grow stronger. This is a way of levelling up everyone at the same time.

Level Up

Be sure that you are usually fighting in random battles, growing your Sphere Levels, and using them on the Sphere Grid to become stronger. There are usually hard bosses that lie ahead, and you won't stand a chance if your characters are tagging along.

Also note that the Aeons strength, defense, evasion, agility, etc. grow along with Yuna. So as she gets stronger, so do your Aeons. Never forget to touch Save spheres now and then if you do not wish to save, so your Aeons and characters gain full HP and MP.

Do the Side Quests

Be sure that you do the side quests, especially the ones given to you in the game, such as the Monster Arena, Blitzball, etc. These are all ways of getting stronger weapons and armor for your characters. Make sure you capture one of each monster for ten different areas. Not only will you get the Mars Sigil, but you will also get an array of various items, that will make your characters abilities sky rocket, and your characters stats.

Be sure that you play Blitzball. This is the only way to get all of Wakka's overdrives, and his Ultimate Weapon.