Get Rupees and Hearts by Scaring Soldiers
Enter Castle Town as a wolf, and cause cries of distress in the Town Square. Soldiers will come to investigate. Let them get close and surround you. Then, use your Dark Field to Spin Attack. Terrified, the soldiers will run away, dropping arrows, Rupees and hearts for you to collect.
Resume Game in the Dungeons
To avoid having to start all over when you exit a game in the middle of a dungeon, grab your Ooccoo and warp out of the dungeon. Then, save and quit the game. When you resume play, use the Ooccoo to warp back to the dungeon room where you stopped the game.
Use the Ball and Chain to Hurt Enemies
Try throwing the Ball and Chain behind the backs of enemies. It will rebound and slam into the bad guys from behind, greatly weakening or killing them.
Get Rupees by Killing Birds
In various birds of the game, you'll notice evil birds lurking in the sky. You'll see these birds, for example, at the bridge over Lake Hylia and in Hyrule Field. Shoot all the birds with your bow and arrow. Large amounts of Rupees will fall from the sky for you to collect.
Fishing for Rupees
Leave Castle Town by the South Gate and climb up the pillar on your right. Turn into a wolf and dig in the middle of the circle of rocks. Drop down into a cave filled with water and a few islands. Defeat the enemies to get a treasure chest. Turn back into Link, and knock down a bee's nest for fishing bait. Go fishing. The water here is full of record-breaking pike and greengills. Also, you can catch bags of Rupees.
Turn Night into Day
You can only complete certain challenges during daylight hours. Instead of waiting around for daybreak, warp to the City in the Sky. When you return, it will always be daylight.
Get Unlimited Rupees for Powering Magic Armor
Catch all 60 Poe Souls and bring them to Jovanni. Speak to him again, and he will give you 200 Rupees. Walk away, then return and talk to his cat. The cat will give you another 200 Rupees. Keep repeating until your wallet is full.
Stop Ganondorf's Attacks
In the last portion of the game when you are fighting Ganondorf, distract Ganondorf by pulling out and waving your fishing rod at him.