Damage Boost

Damage boosting is a means of crossing longer gaps than intended using the pushing force of taking damage, often from a well-timed and well-placed explosion. There are two main types of damage boosts used in practice: ledge boosts and mid-air boosts.

Ledge Boost
A ledge damage boost occurs if Link is hit by an explosion at the correct time while climbing from a hanging position on a ledge. The explosion instantly puts Link to a standing position at the edge while simultaneously pushing him off at full speed. This allows you to get a bit of extra jumping distance, making that ledge on the other side reachable when it wasn't before. A ledge boost is the damage boost of choice if you'll need to grab a ledge on the opposite side of the chasm.

To perform a ledge boost, place a bomb near enough to a ledge such that the explosion can hit Link from a hanging position on that ledge. Go hang off the ledge. Safe and reliable ways to hang instead of jump are backwalking or a dry roll. After hanging, pay close attention to the bomb. Just as it starts to fast flash, begin climbing up the ledge. When the bomb explodes, it will push Link off. Hold the analog stick in the direction of the jump for maximum distance.

A good example of a ledge boost in practice is in Death Mountain Crater where we can jump from the ledge near the ladder to the ledge near the Great Fairy Cave despite the boulder being in the way. This allows early access to the Bolero of Fire cutscene, and Darunia's chamber in Goron City.
 * At 0:05 we try to make the jump with a good angle. It fails because it's too far to make by normal means.
 * At 0:15 we do a setup to get in a good position and angle for this particular ledge boost. The setup here is target the wall, get into the left corner, do two sidehops to the right, then three backflips.  From that position and angle, the boost will reach the ledge on the other side.
 * At 0:20 we place the bomb at such a time as it will explode at the same time as we climb up the ledge we are about to hang from. In this instance, we place the bomb right around (not precise) the second red flash.
 * At 0:23 the damage boost is successful.

Mid-Air Boosts
A mid-air damage boost occurs when an explosive that Link is holding explodes while Link is already in the middle of a jump. The explosion damage will throw Link away from the source, giving you more distance than normal. This is often paired with mashing a jumpslash input during the explosion to get even more distance.

There are a couple of ways to perform a mid-air damage boost. The first is to pull a bombchu and wait until it will soon explode. Jump off a ledge while holding target at such a time as the bombchu explodes when you are in the air. Once you are in the air, mash the B-button to ensure you get a jumpslash just as the bombchu explodes. The second way skips waiting for the bombchu. Instead you shield-drop it mid-air, thus making it explode exactly when you want. You'll still want to get a jumpslash in as it explodes, however note that you can not jumpslash while holding shield in mid-air. Thus you'll need to practice pressing shield for a very short duration so you can squeeze the jumpslash between the shield drop and the explosion. The first of the two above methods is often used in routes where Link does not have a shield.

A good example of where either of these two methods is useful is boosting to the small ledge before the crawlspace to Hyrule Castle Courtyard as child Link. This allows one to skip the conversations with Malon and Talon and waiting the day cycle for the egg to hatch.
 * First is the shield drop method. At 0:04 the wall is targeted to lock a straight angle relative to the ledge. We turn around and hold target.  Note that target is held for the duration of the trick.
 * At 0:06 we pull a chu and run off the ledge, pause buffering (excuse the bad buffering) to either the first or second frame Link rises from his jump. Note that other instances of a boost like this might call for different frames.
 * At 0:14 we get to the second rising frame of Link's jump. We then buffer one frame of a shield input to drop the bombchu.
 * At 0:17, when the chu is already down and about to explode, we buffer in a B-button press for the jumpslash out of unpause lag. Success!
 * Next is the timed explosion method. At 0:24 the wall is targeted once more to lock the correct angle. We turn around and pull a bombchu and backwalk against the wall so we know for sure our front to back position. Note that target is held for the duration of the trick.
 * At 0:30 we pause on one of the five frames that this boost will work on. These frames are the brightest frame of the 7th red flash and the four following.
 * At 0:32 during unpause lag we hold forward to run off the ledge. As soon as Link is airborne (and not before) we begin to mash the B-button for the jumpslash.

Combining Ledge and Mid-Air Boosts
In some special cases, one might want to ledge boost of the edge of a chasm, and immediately use the shield drop method of a mid-air boost for even more distance. This is useful in two notable places in Shadow Temple in Glitchless Any% to facilitate skipping the hover boots: the chasm near truth spinner, and the room with Bongo-Bongo's boss door.
 * At 0:05 a good position in the center and a straight angle towards the destination platform are acquired.
 * At 0:07 a bomb is shield dropped near enough to the ledge that its explosion could reach Link from a hanging position. We then dry roll to hang off the ledge.
 * At 0:09 the bomb begins flashing quickly, signaling we need to begin to climb for the ledge damage boost.
 * At 0:10, as the bomb explodes we hold target to lock a good angle, and forward to get momentum in the jump direction. The ledge boost is successful, but not enough on it's own.
 * At 0:11 we wait until the approximate apex of Link's jump, pull a bombchu, tap shield to drop it so it explodes, and immediately mash B to get the jumpslash. Note that target is held for the duration of the mid-air boost. Note also to not hold shield longer than it takes to drop the bombchu, as you can not jumpslash while shield is still held. The double damage boost is successful!
 * At 0:26 the same trick is used in the room before Bongo Bongo. Note that in the mid-air damage boost a slightly upleft angle is used to reach the platform.
 * At 0:57 we do the same trick again in the same room, but this time with the Lens of Truth on so it is apparent why the trick is necessary, and where the platform edges are relative to the damage boosts.