Secret Place Coordinates
When you have an airship, talk to Cid, and choose the second option in Map menu (Search). The secret place are:

Secret Place #1 X: 34 Y: 58
Secret Place #2 X: 15 Y: 41
Secret Place #3 X: 31 Y: 73
Secret Place #4 X: 16 Y: 57
Secret Place #5 X: 42 Y: 57
Secret Place #6 X: 74 Y: 36
Easy Blitz-Ball moves
To learn Blitz moves faster just set your marks on the move you want... now when playing dont worry about setting your players to "mark mode". You don't need to as long as they use their Blitz move you can copy it! Now your players wont run from their positions when in "mark mode". You must do this before fighting the last boss because the boss (Sin) will enter your summon body to take over the body. So, you must kill all your summon to fight the last boss. This battle will be easier if your summon don't get to their highest power.

Steal From Chest's Without Fighting Mimics
Later in the game you will incounter treasure chest's during battle. Some of these chests have nothing in them and as a result you have to fight a powerful mimic. But there is away around this. First make sure Rikku (or anyone) has the ability "Mug." When in a battle with a chest, use mug on the chest, if the chest has an item, you get it and kill the chest. If not, you get no item and kill the chest. Since chest's have 1 HP this is a great way to avoid mimics.

Get the NO AP Ability Off Your Legendary Weapon
To get the NO AP ability off your ultimate weapon , you must collect the correct crest and sigil for the weapon.

More Potions
On the USS Likki, the first time you get on there, go down into the lower part of the ship and enter the room with the two Besaid Aurochs. After getting the chest in that room, go up to the suitcase and press 'X'. Tidus will kick the suitcase and get a potion. Keep kicking it and the suitcase will give you more and more potions until it totally runs out.

One of the Best Blitzball Shots
On the S.S. Winno you will get the Jecht Shot Challenge. If you pass it you can use the Jecht Shot in blitsball when you pass level 3.

Get tons of AP
To get a lot of AP any time after you kill Seymour the 1st time just return to Macalania Temple and fight the Guado.

Very Easy Win with YuYevon
I am not saying the boss is easy, but if you manage to make it passed all your summons and you fight Yu Yevon this is what you do. No matter how much you hit him he uses Curage and heals 9,999. So use a reflect on him and hit him. He will heal you 9,999 almost every hit he takes.

Lots of Potions
While riding the S.S. Liki, go to the bottom deck and enter the first door to your left. in the Room their should be a brown briefcase on the floor, kick it 15 times and you will get 15 potions.