I want more!
Now you can continue the main quest by going to the Mountain area or stay longer in the surroundings to get more items: two masks and three Pieces of Heart.
Leave the temple area through the north, dive in the Deku flower and fly towards southwest to return to the Deku Palace. Go to the Royal Chamber and free the princess in front of the king. She orders to free the monkey. The monkey thanks you and says that a gift is waiting for you in the shrine. Leave the palace, go on your right as soon as you walk past the two Deku scrubs, remove your mask and swim towards northwest to reach the Deku Shrine. There you will meet the Deku butler who asks you to follow him. Wear the Bunny Hood (without it the race will be very difficult) and don't lose sight of him to keep up with him. When you see a diamond, shoot an arrow at it to chase the flames and go on. Soon after that, you join the Deku butler who will reward you with the Mask of Scents!
Go back to the Swamp Tourist Centre (you can use the Owl Statue as a shortcut). Talk once more with the witch who will offer you a game. (If you already played the Song of Time after finding her in the Woods of Mystery, you will have to rescue her once more.) You will have to hit targets 20 times at least to win a Bottle (3DS version) / a Piece of Heart (N64 version), the game will cost you 10 rupees on your second try.
The Mask of Truth is the present you will receive after looting 30 Gold Skulltulas Spirits in the Fearful Spider House, you can check this in the related Tips and Tricks chapter.
If you still haven't won the photo contest, go back to the Deku Palace after having played the Song of Time (the contest is over after beating Odolwa). Take a picture of the king and bring it to the man at the Tourist Centre desk to get a Piece of Heart.
During daytime, go back to the Termina Field. In the southwest part of it you will find a very large pack of bushes with a Deku baba in the middle. Run around it until you drop through a hole, then get rid of the "Peahat" by hitting its sting to win a Piece of Heart.