Proceed through the storyline until you get the chests in the chieftess'
hut at Woodburrow that the person refills every day. Then, open the
chests, and collect the coins. Go to the "Level Select" screen, and
enter a level. Once the level begins, open the menu, and return to
Woodburrow. When you enter the town again, the chests will be refilled.
Repeat the process as many times as desired to get an unlimited number
of coins. You get approximately 440 each time, and it takes 30 to 45
seconds to repeat each time.