Second Quest
"The Legend of Zelda" is divided into two quests. For the most part, they're identical except some items are moved for the second quest. The second quest also has tougher monsters. Typically, you can only access the second quest by beating the first quest. If you want to skip right to it, start a new game. When prompted, enter "Zelda" as your name. Instead of starting in the first quest, you'll start in the second.
Save Anywhere
Typically, you can only save the game when you die. By pressing "Start" on your controller and then pushing "A" and up at the same time, you can summon a secret save menu. This lets you save anytime and anywhere. This trick is especially useful before playing the gambling game. Save and place a bet. If you lose, reset. If you win, save and place another bet. You can rack up a quick fortune this way.
Bubbles
Bubbles resemble floating skulls, typically red or blue flames around them. If a blue hits you, you become temporarily invincible. Although you still take damage from the bubble's attack, you can use this trick to escape hairy situations. If you're mobbed by several tough enemies, simply run into the bubble to become invincible. After that, flee the room, or, if you're feeling up to it, attack the enemies without fear of immediate reprisal.
The Wizzrobe Trick
Wizzrobes come in two varieties, orange and blue. Orange ones are weaker than blue ones. If you encounter a mixture of orange and blue wizzrobes in a single room, kill all the orange ones and then exit the room. When you return, several of the blue wizzrobes will have transformed into their weaker orange counterparts.
Digdogger Flute Trick
The digdogger is the fifth boss monster. Although it's tough, you can beat it with a simple trick. The digdogger doesn't like loud sounds. Drop a bomb, and when it's close to the bomb, play your flute. The boss will freeze long enough for the bomb to go off. Afterwards, it will move very slowly. Hit it once more with your sword to finish it off.