Running low on arrows? dont feel like spending money? go to the bridge of eldin, on the bridge, there should be an archer, go to the archer. Do not kill him, just hold your shield up.He will begin to shoot at you, the arrows he shoots are able to be picked up, so when he shoots one, step to the side and pick the arrow back up. You can get as many arrows as you want!

P.S.You can do this with any archer...