Great Deku Tree - Gohma
Gohma, a parasitic arachnid, dwells inside of the Great Deku Tree. Throw Deku Nuts or use your slingshot on Gohma's eye when it is red. Keep rolling to avoid Gohma's charges, and slash Gohma with your sword.
Dodongo's Cavern - King Dodongo
The dragon King Dodongo is the boss in Dodongo's Cavern. Dodongo attacks by rolling around his circular domain or breathing fire. Make Link stand against a wall or roll himself to avoid the Dodongo roll. When Dodongo opens his mouth, throw a bomb inside.
Lord Jabu-Jabu's belly - Bigocto
Bigocto is an oversized Octorok, an octopus-like creature that shoots seeds from its mouth. Bigocto's primary mode of attack is to chase and knock Link down. Link can roll out of Bigocto's way, or throw a boomerang at him. When the boomerang stuns Bigocto, slash at him from behind.
The Forest Temple - Phantom Ganon
Link faces a replica of the main antagonist, Ganondorf Dragmire, in the Forest Temple. Linger in the corner of the room to avoid Phantom Ganon's lightning attack. Use your fairy bow three times to make him abandon his horse. When Phantom Ganon hurls orbs at you, attack the orbs to reflect them back at Ganon. Attack the stunned Ganon with your sword.
Fire Temple - Volvagia
There are lava-filled holes on the platform where you face the dragon Volvagia. Volvagia will emerge from these holes to swipe at or blow fire at Link. If you see shadows where Link stands, run away to avoid falling debris. Use your hammer to stun Volvagia then slash at him with the sword.
Water Temple - Morpha
Use Z-targeting to attack the shapeless blob, Morpha. This focuses on its nucleus. Use the Longshot on the nucleus to draw it out and attack repeatedly using your sword. Repeat the entire process a few times to defeat Morpha.
Shadow Temple - Bongo Bongo
In the Shadow Temple, Link faces an odd enemy named Bongo Bongo. Bongo Bongo is a large drum with two hands resting on top of it. Roll away from Bongo Bongo's hands, and use the spin sword attack to hit both hands at once.
Spirit Temple - Twinrova
The witch sisters, Kotake and Koume, launch fire and ice attacks at Link. Dodge these attacks, then use the Mirror Shield to reflect one sister's attack at the other. When the sisters combine to form Twinrova, use the Mirror Shield to collect three of either element in a row. Let the resulting energy beam reflect at Twinrova. The stunned Twinrova will fall, allowing Link to slash her with his sword. Repeat the process to defeat Twinrova.
Ganon's Castle - Ganondorf
Equip the Hover Boots. Linger along the outer edge of the room and use your sword to reflect Ganondorf's attacks back at him. Use a light arrow to stun Ganondorf, then slash him with your sword. Repeat until he transforms into Ganon.
Ganon's Castle - Ganon
Roll between Ganon's legs to get to his backside. Use the Megaton Hammer or one of your swords on his tail. Repeat this process until he is temporarily stunned, which will give you time to get the Master Sword. Try to get Ganon to attack the ruins around him to get special items like magic jars and arrows. Focus any attacks on Ganon's tail. It will take about 10 hits to finish him off.