This trick allows you to store the coordinates that are set when the Links jump down ledges, and lets the Links jump to them later. Releasing storage on a different screen from where you did it lets the Links jump to unintended places.
However, you cannot store coordinates past TV screens unless you transition by stairs, but it is possible across all GBA screens within one TV screen.
Depending on the way this trick is executed, you have various options of time and space to release the storage.
You must be in a C-Formation so you can actually control the other Links as Green jumps down.
Sometimes, usually after you used Jump Storage, it can happen that, while Green Link jumps down, the other Links will disappear and then reappear and move to Green as he lands. To fix this, you simply have to switch screens.
When releasing the storage, most of the time the Links will jump into OoB area, but pressing X at the correct moment might avoid this.
Usually, when doing storage GBA->TV, the Links will jump to the top of the screen, and for TV->GBA to the bottom right corner.
The stored coordinates gained by the ledge jump affect the positioning on the other screen, but the previously mentioned attributes maintain.
When you pick up a Link as you release the storage, the carried Link will keep the storage effect until he touches the ground again.
When Green jumps down, press and hold B so the other Links will use their sword, unable to jump down as well.
Exception: You can also press B+R to hop down a ledge without any timed inputs, but then Greens movement is restricted to those hops.
Also, this method has a time limit until the other Links will release the storage, and will ultimately be released when changing screens.
Note that you only can move below the row of where the storing Links are positioned, and that they will try to reunite with Green, so you must use your environment wisely.
A more convenient way is charging an item and then simply jump down a ledge. The storage will be activated when you release the A button, so you can access multiple screens.
After a while, the other Links will appear next to Green, and you can get into C-Formations again, without affecting the storage effect.