Unlook Door in Level 1
Once you enter Level 1, there is a locked door straight ahead. Leave the dungeon and re-enter and the door will be open.

Faster way to Level 9
Once you have collected all the pieces of triforce, go to the outside of Level 8, and blow the whistle. It will take you to the outside of Level 9.

Get Rupees and Hearts Fast
Go into the graveyard, and touch each grave so a ghost comes out. Now go and kill the first ghost that was on the screen and every ghost will disappear leaving hearts and rupees.

Quick Save
Press the start button. THen on controller 2, press the UP and A buttons and the continue, save, retry screen will come up.

Avoiding enemies
When you are on a battle screen, kill all but one enemy. Each time you return to that screen, only that one enemy will be there and the others wont come back.

Killing enemies easier
Once you enter a screen full of enemies in the overworld. Kill the weaker enemies, leave the screen, and re-enter the screen. The stronger enemies will be gone, and they will be replaced by weaker ones.

Second quest dungeons
Some of the dungeons in the second quest have hidden doors. Never trust the dungeon maps in the second quest. If there is a place where you cannot reach through a door or using a bomb, go to the surrounding rooms and try walking through the wall in the direction of the door. Also, even if the map doesn't show a room, try doing so as there are rooms that don't even appear on the map.