We've found that the easiest way to defeat Gohma is this: When she first jumps down on you, stun her with a Deku Nut. Then z-target her and hit her in the eye with your sword. Keep her z-targeted while she climbs up onto the ceiling. Once she is on the ceiling, wait unitl she starts to hang upside-down. When she does that her eye will turn red. Shoot her with your slingshot. She will fall to the floor, stunned. Keep her z-targeted and hit her with your sword. Repeat this process two or three times to defeat her.
To defeat King Dodongo, you must do as follows: Wait unitl he starts to draw in his breath. Now quickly throw a bomb into his mouth and stand back. After he explodes, run up and hit his face with your sword. Now run to the wall and stand as close to it as you can. He will start rolling around the room. Now run in front of him and do the same thing again. Repeat this process about three times to defeat him.
Barinade is a little bit harder than the last two. To defeat him you must: Z-target him and hold the C buttom that your boomerang is on. Keep him z-targeted and run around him in a circle. While running, throw your boomerang at him. Run up to him and hit him with your sword while he is down. Repeat this process a couple of times. Now when you hit him the gold bariers will dissapear from the jellyfish that surround him. Use your boomerang to defeat as many jellyfish as you can before he starts spinning again. After you repeat this process a couple of times, the jellyfish will leave and he will spin around by himself. Remember to keep him z-targeted at all times. Now hit him with your boomerang. When he falls to the ground, hit him with your boomerang again. Repeat this process a couple of times to defeat him.
To defeat Phantom Ganon, you have to do this: He will jump into one of the many pictures surrounding you. Keep your eye on all of the pictures around you. He will start riding out of one of them. When he first jumps out, shoot him with your bow. He will withdraw back into the picture. Repeat this process unitl he comes out of the pictures and starts flying around the room. While he is flying, he will begin to throw blue fireballs at you. Z-target him and stand still. When one of his fireballs gets right in front of you, hit it back at him with your sword. He will hit it back at you so just hit it back to him. You will continue doing this a few times. After a little bit, one of the fireballs will hit him. He will fall to the ground and stay there for a little bit. While he is down, hit him with your sword as many times as possible. He will then start flying again. Repeat this process a few times to defeat him.
Volvagia is one of the easier bosses in the game. To defeat her, you have to: Wait until she pops her head out of one of the holes. When she does, hit her with your megaton hammer as many times as you can. She will duck back into the hole. When she comes up again, she will start chasing you around the room. Run away from her until she goes back into one of the holes. Repeat the process a few more times. Eventually she will drop rocks on you when she is flying. Keep repeating the process to defeat her.
This is how to defeat Morpha: Z-target it and wait for it's nucleus to start spinning. When it starts to spin, back up to a safe distance. It will throw one of it's psuedopods out of the water with it's nucleus inside of it. Use your hookshot to grab the nucleus and pull it towards you. When it comes to you, hit it with your sword. Repeat this process several times to defeat Morpha.
Bongo Bongo is considered one of the harder bosses in the game. To defeat him you have to do as follows: Hit his both of hands while he is banging on the drum. Now use the lens of truth to spot his eye. (It is between his hands) Hit his eye with your sword as many times as you can. Stand out of the way when he starts to move towards you. Repeat this process a few times to defeat him.
Twinrova, in our opinion, is the most fun boss in the game. While they are flying around, they will alternately shoot fire or ice at you. Use your mirror shield to deflect the attack. A beam of fire or ice will shoot off of your shield. Use the beam to hit the opposite witch of the one that shot at you. After you repeat this process a few times, the witches will put their powers together and turn into one witch. She will shoot fire or ice at you alternately. Try to catch three of the same attacks on your mirror shield. When you do, a beam of either fire or ice will shoot off of your shield. Use it to hit the witch. She will fall onto one of the platforms outside of the main platform. Hit her with your sword as many times as you can. Repeat this process a few times to defeat her.
To beat Ganondorf, you need to do as follows: Run close to the wall before he knocks out part of the floor. Stand facing him with your sword drawn out. He will throw fireballs at you like Phantom Ganon did before. Hit them back at him with your sword, and he will hit them back at you. Keep hitting them back and forth unitl one of them hits him. Quickly, shoot him with a light arrow to knock him down. Run up to him and hit him with your sword. (It helps to use your hover boots to run across the gap that he made.) After he gets back up, run to the wall and face him again. Repeat the process two or three times to defeat him.
After you defeat Ganondorf, he will turn into Ganon. To defeat him you must: Z-target his face and shoot him with a light arrow. While he is holding still, run behind him and hit his tail with your Biggoron's sword. (If you didn't get it during the game, you could use the megaton hammer instead.) Repeat this process several times. (If you run out of magic you can roll in between his legs to get behind him.) After awhile, the ring of fire around the area will dissapear. Run to get the Master Sword. Repeat the same process as you did previously except with the Master Sword. After awhile, he will fall to the ground and Zelda will tell you to give him the final blow. Hit him in the face with your sword. The sages will take over from there.