The Superslide is the fastest known method of travel in the game, so it is a highly desired trick for speed runs. Because of its speed, hover boots can be equipped after starting a superslide to hover over large gaps. It is also fast enough to clip through some areas, such as the Deku Tree as Adult. In addition, a superslide can be used to skip certain cutscenes, such as the owl texts. There can be odd effects when holding a superslide through cutscenes, and even allows you to keep the Master Sword in the Ganon cutscene.
A Superslide is set up similar to a ground jump; however, the timing is much more precise. The easy, automatic way is to cast Nayru's Love, and then set up a Ground Jump. After you are hit by the damage (bomb, enemy, etc.), instead of storing the jump you will do a superslide.
However, Nayru's Love is not very practical. It takes a lot of time to cast the spell, and to even get in the first place. The harder but more common way requires: A Grabbable Object + Source of Damage. The most common object to use would be bombs, as it is both the object Link can grab, and the source of damage. In order to get a good set up, backflip, and immediately shield drop a bomb by pressing the bomb C-button and R for your shield. You should now be about a roll's length away from the bomb. Your action icon should read Attack, not Grab. Hold Z and R, and wait for the bomb to nearly explode. About 40 frames before it explodes, roll into it by pressing A and then again press A to "grab" the bomb. If done correctly, Link will roll forward, the bomb will explode just before he finishes his roll, and push him backwards at superslide speed. The superslide will continue as long as you continue to hold down R.
Another method to set up a superslide using a bomb:
The timing for the mashed roll is very precise and requires practice in order to become consistent at it. With enough practice you should be able to superslide in this manner with a 50%-80% success rate.
It is also possible to do a backwalk superslide. This has the extra speed advantage over the stationary set up in that you can pull the bomb and already be backwalking to your destination. Of course, this method is also a bit harder. As you are backwalking you must release the bomb just about when it starts to flash quickly, and take another step or two back. Then you can roll into and try to grab it just as you would with the other methods.
Superslides work by shielding damage at the same time as trying to grab something. With one bomb, the timing is very strict as you have to grab the bomb as it is exploding. By using two bombs, you can shield the explosion of one bomb while grabbing a separate bomb, thus giving you many more frames on which you can successfully get a superslide.
For a two-bomb superslide, you need to drop the bombs as shown in the video and mash A to roll and grab the second bomb just before the first bomb explodes. For a backwalking superslide, you need to shield drop the first bomb on the third flash, then immediately shield drop the second bomb and proceed as you would with a one-bomb backwalking superslide. The video below shows first a backwalking two-bomb superslide and then a normal two-bomb superslide.
Superslides can be done without bombs. You just need another grabbable object and another source of damage. The grabbable object can be bushes, pots, bomb flowers, etc. The damage can be most enemy attacks, ones that don't knock Link over and his shield will block. Now stand in front of the grabbable object, and hold Z and R. The trick is to roll forward, and just as Link is about to finish his roll, have the enemy attack him and he will block it with his shield. If done correctly, Link will block the attack, but will be shot backwards at a great speed, and will still have the A button say Grab. Again you can keep the superslide as long as you hold R.
If the object you are interacting with is something that Link cannot pick up, such as bomb flowers or grass before you get a strength upgrade, it is possible to do what is called a superslide teleport.
In order to do this, first get a typical superslide off one of these objects. Note that it must not break in an explosion; the original object must still be intact so you can grab it, so if you use bombs or bombchus be careful of the set up. After getting the superslide and being shot back, let go of R, and you will be shot back to grab the object. Link will grunt and won't be able to pick it up. Note that if you superslide too far you will no longer be able to teleport back to the object.
The trick is useful however, because of one extra characteristic: When you warp back to the object, the Z position of Link does not change from where he teleported from. This means that if you superslide up a hill or slope and then warp back, you will be over top of the object you are trying to grab, and if you performed ISG beforehand you will stay there in the air. This is useful in some cases to get Shadow Temple Early. Additionally, if you go down a slope and warp back, you will be out of bounds below the object. This can be useful in certain situations as well, especially where there is out of bounds water to swim in.