Spindash
Spindash is a glitch that most notably can be used to put Link in the Superspeed glitched state. It can also be used for some Out of Bounds tricks.
When in this state, your sword will be disabled, which is a good way to tell if you did the trick correctly or not.
Works on
This is a JP 1.0 exclusive glitch.
How to perform it
Doing a spindash is quite simple: Hold B to charge you sword, and when the sword is charged release B, then press the A button the next frame.
Most people will slide their thumb from B to A quickly to be able to do this consistently.
If you see Link start dashing, you were too early on your press of A. If you spin but didn't get the proper glitched state, then you were too late on your press of A.
Another technique is to roll your thumb clockwise from B to A - if done like this, and you see that Link starts dashing, you have the opportunity to roll your thumb back to B to attempt it again.
IMPORTANT: Don't face a wall or something, otherwise the A input will make Link try to grab that instead of dashing. That's why we face up or down on stairs while doing this trick.
You can cancel this state by pressing A, screen transitioning, or jumping off of a ledge, to name a few.