Rupees are the lifeblood of Link's adventure, used to purchase essential items, upgrades, and even continue your game. While enemies drop Rupees, there are several hidden spots in the Overworld where you can acquire large sums of Rupees quickly. These 'money making' spots are invaluable for stocking up on Bombs, Arrows, and other costly items.
One of the most famous money-making spots is located in the eastern part of the Overworld. From the starting cave, head one screen north, then one screen east. You'll see a lone bush in the middle of the screen. Burn this bush with your Blue Candle to reveal a secret cave. Inside, an Old Man will offer you 30 Rupees for a small fee (usually 10 Rupees). You can enter and exit this cave repeatedly to farm Rupees. Another spot is in the western part of the map, two screens west of the starting cave. Bomb the northern wall to find a similar cave. Utilize these spots whenever you're low on funds to ensure you're always prepared for the challenges ahead.