If you want easy rupees use the bomb mask or bombs on the wall in the tower you get the moon's tear from just take the side path as soon as you get in past the bomber kid. There is a chest with a silver rupee worth 100 Another easy way is blackmail Tingle's dad (he runs the photo contest) with a photo of Tingle another easy 100 rupees. Lastly memorize the lottery numbers for each day.