Infinite Lives
While playing World 2-3, you will come to a staircase with a turtle descending just past two Piranha plants. Wait for the turtle to go off the third step from the bottom and jump on top of it. Your character will then pounce on the turtle multiple times, earning you up to 99 lives.
Another spot to get infinite lives is in World 7-5. In the section where two Bullet Bills are firing, pick up and throw a Koopa shell in between the cannons, and you will be rewarded an extra life. You can repeat this every four seconds to earn multiple lives.
Easy Coins
An easy way to get coins is to extract them from dancing flowers. To do this, stand still on top of one of these flowers, and then perform a spin jump. You will be rewarded with a coin. Do this on all dancing flowers to accumulate a large amount of coins.
Protect Your Head
If you find a small item such as a turtle shell, you can use that to protect your head from falling objects. Stand next to the shell, press ̶0;1,̶1; and shake the Wii Remote to pick it up. Mario, or whomever you are playing as, will hold the shell above his head, giving you defense from falling objects.
Super Guide Mode
If you are stuck at a particular point in the game, you can initiate Super Guide Mode, which will effectively beat the level for you. All you have to do is die eight times in a level and you will be given the option to turn on auto pilot. Initiate auto pilot by hitting the green Super Guide block.
Double Ground Pound
With multiple players in the game, you have the ability to perform a double ground pound that will instantly kill all nearby enemies. To do this, you and another player will both need to jump and ground pound at the same time. If timed correctly, your characters will perform a larger-than-usual ground pound.