First of all, according to ZeldaSpeedRuns.com:
In Ocarina of Time, a wrong warp is an incredibly complex glitch that allows you to enter different scenes (areas) than one expected. It is done by stepping into a blue warp, using ocarina items to maintain control of Link, then changing your location on a certain frame.
You can check the url above for more specific details, but it comes down to a combination of the scene entrance table index (which determines what scene/room/map to load and the coordinates in the room at which to place Link after a cutscene, room entrance, or death), and the active cutscene state value (which offsets the entrance value based on the cutscene which was last played). A more detailed explanation is available at the given url, but by executing one of a number of sequences of glitches, you can manipulate these two table indices to cause Link to load in the wrong level.
There are a number of methods available for wrong-warping, and while they are all specified and illustrated in detail at the link above (as well as in various YouTube clips and on SpeedDemosArchive's and ZeldaSpeedRuns' websites). At the time of writing this, these are the only well-documented methods available on the ZeldaSpeedRuns website. I will go over them in brief detail:
Boss Door Method
This method is, to my knowledge, exclusive to the first dungeon (Inside the Deku Tree). The procedure is as follows:
- Reach Gohma's chamber.
- Before delivering the final blow, ensure that you have only half a heart left.
- Deliver the final blow by standing close to her and using a jump slash into her.
- If done correctly, this should cause you to die as Gohma is defeated.
- Continue playing, and return to Gohma's chamber.
- When in Gohma's empty chamber, perform the Ocarina Items trick with a bottled item, and backflip so you land just onto the edge of the blue warp area.
- AS YOU LAND, pull out the "Ocarina" item, and hit B to cancel the item.
- On a specific frame (the site gives little detail on how the timing works; it is probably a matter of estimation and practice), open the door out of Gohma's room.
- You should arrive as young Link at the Tower Collapse stage in Ganondorf's Tower.
Death Warp Method
This method makes use of death warping, a phenomenon where you resume from a specific point after dying (which, by the way, is frequently used in many different games for speedruns, and has varying effects per game). The Death Warp method for wrong-warping can only be used with the blue warps in the Deku Tree, Dodongo's Cavern, or the Fire Temple. The general procedure is as follows:
- After defeating the boss of the temple, approach the blue warp.
- Ensure that you are one bomb-hit away from death.
- Drop a bomb near the warp.
- Perform the Ocarina Items trick with a bottled item, and backflip so you land just on the edge of the blue warp area.
- If done correctly, you will pull out the "Ocarina" item, and the camera will distort.
- On a specific frame (again, no details are available to me at the time of writing this), hit B to cancel the "Ocarina" item and die.
If done correctly, you will warp to:
- Dodongo's Cavern (if done in the Deku Tree)
- Gerudo Training Grounds (if done in Dodongo's Cavern)
- Forest Temple (if done in the Fire Temple)
Farore's Wind Method
This method is by far the most flexible and least well-documented at the time of writing, so I will try to do it some justice. By equipping Farore's Wind to the B button through a method known as Bottle Adventure, it can be cast anywhere in the game (assuming your Magic Meter is not empty). By using a specific cutscene skip known as the Farore's Wind Medallion/Stone Cutscene Skip (link unavailable), you can warp to several different cutscenes in the game, including some of the end cutscenes and out-of-bound areas.