Discovered by Fluffy Kitten
These tricks are very similar so they are grouped together. Both can only be done as adult because of the requirement for hover boots.
As adult link, equip kokiri boots, get next to a ledge and place a bomb behind you. When the bomb blows up it should push you off the ledge. On the first frame where link starts to jump off the ledge, pause and equip hoverboots. It you did it at the right time then you should do a megajump.
Hover Boost Edit
Unlike megajump, you only need a source of recoil for this, not necessarily damage, though damage is the most prefered way.
Method 1: Damage (preferably a bomb). When you get hit, on the 2nd frame of visible damage pause and equip hover boots. Unpause and you should be going at a high speed with hover boots which will allow you to cross large gaps.
Method 2: Megaton Hammer Recoil. On the frame where link is pulling his hammer back up after hitting the wall (seen to the right) pause and equip hover boots. This gets more speed than the damage method but it restricted to an area close to a wall.
Method 3: Crouch Stab Recoil. Similar to the hammer boost method except with a crouch stab. On the first frame link has visibly moved backwards pause and equip hover boots and you will gain speed. This is the slowest out of the 3 methods but becuse it requires nothing more than a shield it is sometimes the only option.