Mask Selling
After you first talk to the guard at the Death Mountain Trail entrance, go to Hyrule Market. Then go to the Happy Mask Shop. Talk with the owner and borrow the Keaton Mask. Take that mask back to the guard and sell it to him. Then take that money back to the owner of the store. Borrow the Skull Kid Mask and take it to the Lost Woods. Sell it to the lone Skull Kid that you played Saria's Song to. Then take the money back to the shop. Borrow the Spooky Mask and take it to the little kid at the Graveyard. He loves this make because it makes him look like Dampe. Then take the money back. Now borrow the Bunny Hood. Go and find the Marathon Runner running out in Hyrule Field. He won't pass up the chance to buy this item. Then take the money back to the shop. Now you can wear the Zora, Goron, Gerudo, and Mask of Truth. The Mask of Truth allows you to talk with Gossip Stones and learn secrets.