Marth Tech: Auto-Cancel
Description / How To Perform
You can reduce the amount of landing-lag after aerial attacks by timing your landing at the correct portion of the attacks animation. The correct timing for when you should land is different for each attack, but is always near the end and/or start of the animation. When an aerial attack is auto-cancelled, the amount of landing-lag is reduced to your characters regular jump landing-lag, in Marth's case this is 3 frames.
Difficulty: 
(Intermediate)
Usefulness: (Extremely Useful)
Extra Info
To help learn the timings for auto-cancelling different moves, you can tell if you successfully Auto-Cancelled an aerial by holding shield as you land. The amount of time before your shield is visible should make it clear if your timing was correct, since without an Auto-Cancel it will take significantly longer before your shield is visible.
Auto-Cancelled Nair is good at walling out opponents in certain matchups. This can be mixed up with Nair into
Fast Fall with an L-Cancel to throw off opponent's timings.