This page explains how to carry more bombs, arrows, and other items, as well as how to increase some of your abilities.
Carry More Rupees
Upgrade 1: Kill 10 Gold Skulltulas and collect their tokens, then go to House of Skulltula in Kakariko Village and talk to a human there to get the Adult Wallet, which holds 200 rupees.
Upgrade 2: Kill 30 Gold Skulltulas and collect their tokens, then go to House of Skulltula in Kakariko Village and talk to a human there to get the Giant's Wallet, which holds 500 rupees.
Carry More Deku Sticks
Upgrade 1: Enter the Lost Woods, then go to the left, and go left again. Go to the far end and buy a Deku Stick upgrade from the Business Scrub for 40 rupees. You will be able to carry 20 at a time.
Upgrade 2: Do mask trading as a child until you get the Skull Mask. Then enter the Lost Woods and go right, left, right, left, left. Go to the back and walk around where you see butterflies. There is a hole in the ground near there. In the underground area, put on the Skull Mask and go to the edge of the ledge. The scrubs allow you to carry 30 Deku Sticks at a time.
Carry More Deku Nuts
Upgrade 1: Warning! In the N64 and Virtual Console versions, this upgrade will become permanently unavailable if you get the Poacher's Saw before getting this upgrade! Do mask trading as a child until you get the Mask of Truth. Then enter the Lost Woods and go right, left, right, left, left. Go to the back and walk around where you see butterflies. There is a hole in the ground near there. In the underground area, put on the Mask of Truth and go to the edge of the ledge. Approach the scrub leader and you will be able to carry 30.
Upgrade 2: Go to the first part of the Sacred Forest Meadow in the Lost Woods. Bomb the boulder there and go down the hole. Pay the Business Scrub 40 rupees to be able to carry 40 Deku Nuts.
Carry More Bombs
Upgrade 1: Go to the past and visit Goron City, and throw a bomb at the rolling Goron when he is in the tunnel. He will upgrade your bomb carrying capacity to 30 bombs.
Upgrade 2: Play Bombchu Bowling as a child in Hyrule Castle Town Market to be able to carry 40 bombs.
Carry More Arrows
Upgrade 1: Win the target shooting game as an adult in Kakariko Village to increase your capacity to 40.
Upgrade 2: After rescuing the carpenters in Gerudo Fortress, play the horseback archery game in the Gerudo Fortress area and get a score of 1000 or better. If you don't get the biggest quiver from this, play the game again and get a score of 1500 or better. The biggest quiver carries 50 arrows.
Dive Farther Underwater
Silver Scale: In the past, go to the throne room of Zora's Domain and find the Zora standing at the top of the waterfall. Play and win his game to get the Silver Scale.
Golden Scale: As an adult, play the fishing game in Lake Hylia and catch the biggest fish (which swims near the big log in the middle of the pond) to get the Golden Scale.