Larger seed sachet #1 - In the Lost Woods area where you can play unes with the Skull Kids, there is a target hanging from a large branch. Use your Slingshot an hit the target three times in the centre (you should score 100 points each time you hit it in the centre, so just do this three times in a row). After you have done so, a Deku Scrub will emerge, and give you a larger seed sachet. You can now carry an additional 10 Deku Seeds. This can be done only when you are a child.

Larget seed sachet #2 - Beat the Marksman game in Hyrule Castle Town, hitting all ten Rupees. You can now carry an additional 10 Deku Seeds. This can be done only when you are a child.

Larger quiver #1 - Beat the Marksman game in Kakariko Village, hitting all ten Rupees. You can now carry an additional 10 Arrows. This can only be done when you are an adult.

Larger quiver #2 - Pass the test in the Gerudo Archery area outside the Gerudo's Fortress. You can now carry an additional 10 Arrows. This can only be done when you are an adult.

In the Zora's River area, about halfway up to the waterfall entrance to King Zora's Domain, there's a small log. Stand on it, and Navi will state that some frogs are watching you. If you have returned to childhood later on in the game, you can play songs for them for rewards. There are a total of six songs you can play to them. These are:

Zelda's Lullaby
Epona's Song
Saria's Song
Sun's Song
Scarecrow's Song (I think)
Song of Storms

Playing any one of these songs will result in payment in Rupees. However, if you play all six songs to the frogs, they will reward you with a Piece of Heart.

After you play all six songs, they will ask you to play a game with them. The objective is to hit the correct notes matching the correct frog. Complete this game a number of times (it gets harder every time you play) and you will be rewarded with another Piece of Heart.

Bottle #1 - Find all seven Cuccoos and place them back in their pen for the woman in Kakariko Village. The first time you do this, you will receive an empty bottle. Any other time, you will receive a Purple Rupee (worth 50 Rupees).

Bottle #2 - Return to Lon Lon Rach (as a child) after you have woken Talo up in the Hyrule Castle Courtyard. Enter Talo's house on the Ranch and win his Cuccoo fiding game. You will receive a bottle filled with Lon Lon Milk as a prize.

Bottle #3 - Retrieve the bottle with Princess Ruto's Letter at the bottom of Lake Hylia. This is the only bottle that you have no choice but to retrieve in order to continue with your quest.

Bottle #4 - As an adult, capture all fifteen large Poe spirits from Hyrule Field (by horseback archery). After you have returned all fifteen to the Poe Hunter in Hyrule Castle Town, he will reward you with an empty bottle.