In both The Wind Waker and Twilight Princess, whenever you reset the game, the game will continue to run in the background for a few more seconds while the screen slowly fades to black or white, before dumping the current game and loading the title screen sequence. In Twilight Princess, it was discovered that if you were to fall in quicksand and reset the game at just the right moment, the event that respawns Link will fire while the title screen is loading, allowing you to play on the title screen map.
However, there are a few key differences between the two games. Unlike in Twilight Princess, it's possible spawn in places other than the title screen. And thanks to Storage, it's possible to bring back an item with you.
The trick is also referred to as the Back in Time (BiT) glitch.
Kill yourself on any map, and when prompted to continue choose Yes. Then simply press and hold B + X + Start to activate the glitch. Unlike the other methods, this doesn't require you to be nearly perfect.
The game respawns you at Outset Island. When you respawn, it is believed that all of the previous game data is dumped from memory and overwritten with the game data used for "Title Screen" Link. Within about 4 seconds after respawning, the King of Red Lions appears, starting the title sequence (and for some reason will cause the minimap texture to "sail" off the screen). This leaves you with only about 10 seconds to use one Start/A/B button press without bringing up the menu select screen.
Link start out with full health, and is completely mute for some reason during the glitch.
All triggers leading into the houses appear to lead to nowhere, and only causes Link to get stuck in the transition animation between houses. The entrance to Jabun can be reached by swimming, but trying to enter it also causes Link to get stuck. Drowning in the ocean, or entering Beetle's shop causes the game to think that the first title sequence has ended, and plays the opening story, ending the glitch.
When BiT is preformed (drowning or jumping off a cliff/ledge into a void and resetting) you can climb up steep surfaces that you couldn't otherwise climb up. Another important thing to note is that some ledges, that Link would normally fall off when attempting to jump off them, can be overcome in BiT. This alows you to jump from the bottom of the well to its roof. To do so, position yourself sideways as close to the edge of the well as possible so it looks like Link has one foot standing suspended in the air. From here, use C-up to align the second "2" of the "2002" on the title screen text with the left edge of the well, and the top of the "TM" part of the title screen text with the top edge of the well. Once you have this angle, hold L to get out of C-up mode and simply jump. This is the only known method of dying while in the BiT title screen, as the "Game Over" screen overwrites the Title screen sequence, allowing you to save.