This is a very easy way to get rupees when you're running low, but you first need the gilded sword or the razor sword to make this easy. First go to North clock town and go to the mountains. Then search for Dodongos. Hit their tails and they will die. You can do this to the little dodongos once to get 15 or 20 rupees, or do this to the big ones about four times and get 50 rupees. To make this super easy, you can wear your stone mask. You will get cash in no time!