For this cheat you have to have an item in your inventory that you don't need like the Claim Check after you get the Biggoron's sword. Take out a bottle and equip it to one of your C buttons. Go up to something(a fish, bugs, anything you can catch in a bottle) Go to catch it then press start when your in the middle of swinging the bottle. Then you equip an object to the C button which the bottle was on and that should turn into a bottle. (Remember, don't do this to anything you need to finish the game)