A Long Jump Attack (LJA) is a jump attack that can cover a much large distance within a short amount of time. Not only can it can be used to jump across large gaps, it can also be used to squeeze through a few tight gaps. The LJA is often considered to be a GCN only trick since the easier and more versatile Gale Boomerang LJA is GCN only, however LJAs are not limited to just the boomerang. For example, the Sword & Shield skip achieves an LJA by knocking an enemy into the air, then jumping after it.
Lure an enemy (such as a Bokoblin) towards the spot where you wish to LJA and target it. Strike the enemy to send it flying in the air, then perform a jump attack while it's still in the air.
There are two requirements that have to be met in order for the LJA to succeed, which limits the effectiveness of the LJA somewhat:
As you would expect, the boomerang's gale is treated as a target in the GCN version, as the camera "locks" on to it. However, once the boomerang has been released, you cannot move or press any other buttons or else you'll lose the boomerang as a target.
If you aim the boomerang over a void that has something below it (such as some of the voids in Palace of Twilight), the void LJA method will not work.
In addition, the window in which you can jumpslash and still achieve a LJA varies according to different areas. For example, for the LJA to the monkey tree in the Forest Temple, the window for achieving the LJA is somewhat restricted--requiring you to wait until the boomerang has almost completely returned to Link. While for the early heart piece in the Snowpeak Ruins, you can jumpslash almost immediately after throwing the boomerang and still preform a LJA.
In general, there are three varieties of windows for boomerang LJAs:
For more information on the windows of various LJAs, please visit their respective pages.