The Legend of Zelda: Twilight Princess Cheats

If you go into the fishing hole behind the sign at the very entrance there will 3 little mounds of dirt.

Turn into the wolf and dig these up, earth worms will appear, scoop them up in an empty bottle and use them as bait for your fishing hook to make fishing extra easy!

To easily find the locations of all Heart Pieces, go to Fanadi's Palace in Hyrule Castle Town and pay her 10 Rupees for a Love fortune. You will then see an area in the game that will contain a Heart Piece around it, obtainable in some fashion. You can keep paying her to show you other locations, but she will sometimes repeat the same location a few times over.

Donate 1000 rupees to Goron inside the Malo Mart in Kakariko Village (you must progress past the third dungeon beforehand). Talk to the old Goron outside the shop and complete the quest he offers. Once completed, the second donation amount will be reduced from 2000 to 200 rupees.

In the final boss battle, cast the fishing rod to distract him and get in a few easy hits.