As you complete story quests in Zelda: Echoes of Wisdom, you'll unlock more side quests, so you should make a habit of returning to areas that you've saved from rifts. Some quests are even "connected" to each other, requiring you to complete one to complete another. One of these is "The Fireworks Artist" in Goron City. It's one of Echoes of Wisdom's simpler side quests that won't take much of your time. Doing this quest will allow you to grab an Echo you won't be able to get anywhere else.