Instructions
Defeat enemies. When defeated, enemies have a chance to drop rupees in multiple increments: one, five or 20 rupees.
Open treasure chests, usually located in dungeons. Treasure chests can hold up to 200 rupees at a time.
Slash tall grass with your sword. There can be many items hidden inside the tall grass, like rupees.
Break any pots you encounter by slashing them with your sword, or picking them up and throwing them. Pots, like tall grass, also contain rupees.