Jab Fake

Tap A Canceling
This allows a character to use the neutral A attack over and over again, with little lag in between, by interrupting the window on the follow up move with a crouch, which the window often extends well after the actual duration of the move, and holding down-behind doubles as being able to jab while crouched/getting into a crouching position. Also known as IASAing. Peach for example:

Slap 1 Total frames: 19 Hit frames: 2-3 Window of the second slap: 3-25

If you were to time Slap 1's normally while standing, you wouldn't be able to Slap 1 again until the 26th frame by waiting out the 2nd slap window. By IASAing with a crouch (it also cancels the Slap 2 window) you can follow up with another Slap 1 on the 17th frame. That's a very big difference comparatively. By holding down/away instead of tapping down you don't have to worry about timing the crouch as it's done the 1st moment you can, and you don't have to waste time to get the stick back into a neutral position to do the jab, allowing you to do it slightly faster for the most part. It has to be perfectly diagonal though so make sure it's firmly pressed into the notch on the controller, or you will d-tilt or turn around f-tilt instead. A pretty obvious downside for doing it that way, however, would be if you were to get hit out of the jab by something you would be DIing it terribly.

Thanks to Magus420 for this term.