Paper Mario: The Thousand-Year Door Cheats

Get both the W emblem and L emblem and put them on, Mario's hat and shirt will be purple and his overalls will be purple, just like Waluigi.

When you go to keelhaul key, go left out of the village. Go up as far as you can. A mole will pop up out of the ground. Hit the mole with the hammer and you will recieve a whacka-bump. Exit the area, then hit him again. Repeat this untill your inventory is full. When it is, go to the shop and sell them. You will recieve 50 coins for each whacka-bump. This will only work a certain number of times.

If you make a Poison Shroom from Zess T. (a Slow Shroom and an Inky Sauce), the effect will poison you. If you have the Feeling Fine badge on, however, it may do one of 2 things:
1) Heal you to max
2) Cut your HP in half
Be wary when doing this.

If you use an FP-Consuming attack outside of battle(Such as a Spin jump) and get a first strike, you will use that move automatically in battle without using any FP at all.

Missed any Tattle Logs, particularly boss logs? They are not gone for good. Check Professor Frankly's yellow trash can. You will find Tattle Logs thrown away for bosses and other once-only enemies. The log will only appear in the trash once you've gone past the last possible point to Tattle that enemy.

This really won't help you in your game, in fact, save before you do this, or you'll lose some game data. -- When you find the Ragged Diary in the Excess Train's Baggage Cart after meeting the ghost, read the diary and the ghost will appear out of nowhere really angry and curse Mario, earning you an instant game over.

In the Palace of Shadow, during the cutscenes before you fight the Shadow Queen, she will ask you if you want to join her (make sure you saved before the cutscenes). If you choose 'Yes', you will get a weird ending for the game in which you join the Queen, and get a 'Game Over'.

Need more Turtley leaves for all of Zess. T's recipes? Easy. One way is to solve Kroop's trouble and he'll give you a Turtley leaf. If you ever need more, simply go in front of his house and behind the front fence and there'll be 3 bushs. Rattle each one and one of them should give out one. The bush that gives out the leaves always change and when you get one, you have to go off screen first and then come back. Quite handy if you want all the recipes.

Buy as many sleepy sheep as you can carry at the Toad Bros. shop and sell them all at the Petalburg shop for a 2 coin profit each.

On the shelf in the top-right hand of the screen in Professor Frankly's house, you'll find the solution for the 4 statues in Boggly Woods.

In Creepy Steeple, after you've freed the Boos, stand still in the main room.
Wait for some Boos to start sticking to you, the use your Super Hammer attack to shake them off. Do this twice, and the Boos will get mad and form the Atomic Boo. When beaten, he will drop the Lucky Start badge. This is needed if you want to fill up your Tattle Log and get all badges.