I want more!
Now you can go on with the main quest by going to the canyon area or you can get more items more or less optional: a bottle, the Giant's Wallet, two masks and five Pieces of Heart.
To get the bottle, climb on a branch half in the water a little before the waterfall. Then use your Hookshot to get to the tree located on a ledge to the south and go from tree to tree until you reach a passage in the east. Once you are in the Waterfall Rapids, get in the water, dive and get close to the beaver. Talk to him, agree to make a race and win both races to be rewarded with a bottle.
The Giant's Wallet is the reward you will get after collecting 30 Gold Skulltula Spirits from the Oceanside Spider House located on the coast. Check the related chapter in the Tips and Tricks.
To get the All-Night Mask, you need the Giant Wallet and 500 rupees. Go to Clock Town, even if you already did, prevent the robber from doing his crime in the north district on the first day at midnight. Then, on the third day at 10pm, go to the Curiosity Shop in West Clock Town and buy this mask for 500 rupees.
If you got Romani's Mask, go to East Clock Town and enter the Milk Bar after 10pm on the first or second day. Talk to Toto in front of the stage, stand in the central spotlight and play the requested notes with your ocarina. Put on the Deku Mask, talk to Toto and use your pipes under the yellow spot. Then, talk to him again as Goron Link and play your drums under the blue spot. Finally speak with him as Zora Link and play the guitar under the pink spot. Gorman will love it, remember old memories and will reward you with the Troupe Leader's Mask.
If you didn't get the Mask of Truth, you can now easily get it after collecting 30 Gold Skulltula Spirits in the Fearful Spider House in the Southern Swamp. Check out the related chapter within the Tips and Tricks.
The first Piece of Heart can be obtained only after beating Gyorg. From the laboratory, swim towards north-east until you see a small boat near the bank. Climb it, then during your travel use the hookshot on the palm located on a small island. During daytime, speak with the fisherman, jump on the island in the middle and pay 20 rupees per game. You need at least 20 points before time up.
To get the second Piece of Heart, you need Don Gero's Mask to speak with all five frogs spread in Termina. If you choose to get it, the following Piece of Heart will be a piece of cake. Read the chapter about Frogs in the Tips and Tricks.
The third Piece of Heart is located on the way leading to the Goron Village. If you still didn't get the above-mentioned Piece of Heart, you need to return to the temple and beat Goht. In the area where Tingle is, jump in the water to the right of the bridge as Zora Link and open the underwater chest in the south part.
To get the fourth Piece of Heart, look for four fishes and put them in empty bottles (in several times if needed). For example, you can find one in the hole behind the Fisherman's Hut. Bring them to the big fish in the Marine Research Lab that will spit out your reward. Be careful! Try to feed always the same fish in the tank!
To get the fifth Piece of Heart, you need to return to the dawn of the first day after beating Gyorg (the Zora musicians must be in their rooms). Then, go to the Zora Hall and get in the room on the right (Evan's room). Throw your Hookshot on the tree over the drummer, then read the book as Zora Link. Both parts of the song will be written in your notebook. Get out, enter the next room and talk to Japas the bassist. Use your Ocarina and play the first part: 3DS: L R Y L / N64: A down right A, then the second one: 3DS: R Y X R / N64: down right left down. Get out, go in the next room and take off your mask. In front of the pianist, play the combo: 3DS: Y Y R L L R Y L + X X Y R R Y X R / N64: right right down A A down right A left left right down down right left down.