Hovering is, without question, the most useful trick in the game. It lets you levitate to nearly any height or distance using only a source of damage. It is also quite easy to do, so new players should definitely master this technique.
Hovering requires ISG. As you may have noticed, ISG prevents you from falling off edges when on the ground. When you shield damage in the air, the game temporarily places Link in the grounded state before he starts falling. Since ISG doesn't allow Link to start falling when on the ground, it makes Link stick in the air if he shields damage while not on the ground.
All hovering starts with getting ISG. After that, there are multiple ways to hover:
Hovering from the ground requires you to be quick, or Link will fall to the ground after the first hover.
Hovering from the ground is easier if the second hover is done with a Bombchu or Blast Mask. However, it is doable with 2 bombs using the "staircase" method.
You must Z-target something in order to get out of your locked camera while hovering. This could be an enemy or even a bomchu that you shield to hover with. Simply do a normal hover and hit Z afterwards, and your camera will unlock. After unlocking the camera, if you used a bombchu, you will notice that you won't be able to easily change direction.
To change direction hold forward, and slowly move the joystick to the left or right. You will see Link turn slightly and he will be walking forward. During this, quickly let the joystick go to neutral, then hit a direction to change to.