After performing certain actions, Link is left with a short period of endlag where he can't use items or sword slash. You can cancel this endlag early simply by having the circle pad held in any direction during this period of time.
AEC can be used to cancel the endlag that occurs after certain items are used.
AEC can be used to cancel the endlag that occurs after unleashing a spin attack. Note that this cancels not only the endlag but also the spin attack's hurtbox. In some cases, you may want to let the spin attack play out.
AEC can be used to cancel the endlag that occurs after throwing a player or object.
Throw endlag cancelling can be used to throw a player or object and use the Boomerang to catch it on its way down.
Throw endlag cancelling can be used to throw a player or object and use the Gripshot to latch onto it on its way down. This is useful for launching yourself forward off of a ledge.
If the circle pad is held in any direction when coming to a stop after cancelling a dash, Link enters a dash recovery state where top movement speed is lower. If you instead keep the circle pad neutral the moment the recovery ends, you can avoid this recovery state.
After landing from a fall, Link enters a brief recovery state where he bends his knees and cannot move. This state can be canceled by tapping the L or R button just before landing.