Instructions
Become a wolf and dig a whole in the top of a pillar where there is a circle of rocks. This pillar can be found after exiting Castle Town through the south gate. After dropping down into a cave filled with water and two small islands, kill the enemies for a chest. There is also a bee hive that you can knock down and use for bait. Use your fishing rod to go fishing. Almost every other cast you make will get you a bag of rupees.
Stock up on bombs and lantern oil after you have filled your third Vessel of Light and are in human form. Go to Lake Hylia and head up to the Howling Stone high up on the cliff. Behind it is a cave masked by a wall that you can destroy using one of your bombs. If you bomb the walls all throughout the cave, you will find enough rupees to fill your wallet.
Go find the dog and his bone near the Castle Town West Gate. Play fetch with him, except throw the bone in the patch of grass to the right of the doctor's house and instead of bringing back the bone, he'll bring you back a rupee. You can do this as much as you want.
Go to the bridge over Lake Hylia. Kill all the birds with your bow and arrow and then collect all the rupees that fall down from the sky.
Shoot the bell in Kakariko Village with a bomb arrow to get a silver rupee worth 200 rupees. You must be able to turn into a wolf whenever you want and be able to make bomb arrows. You will need to be a wolf to jump on top of the building first.