Z-Cancelling
Z-Cancelling is a technique that allows a character to cancel out the animation that follows certain moves in order to continue chaining hits in a combination. When the character delivers a blow which starts in the air and drives into the ground, hitting "Z" as contact is made negates the follow through animations.
Fast Falling
Pressing down on the control stick while traveling through the air causes a character to rapidly descend to the ground. A fast fall can be used defensively to avoid an attack, or offensively to rapidly position your character to attack.
Quick Recovery
When hit with an attack which causes your character to fall onto his back, he must stand back up to get back into the fray. By hitting the "Z" button at the moment you land, however, your character pops back up quickly, making you less vulnerable to combo attacks and allowing you to catch an opponent off guard.
Button Sliding
Button sliding is not an individual move performed by the character, but rather the act of sliding the fingers from one button to an adjacent button on the controller, instead of pressing the first, lifting the finger up and pressing the second. A properly executed slide allows for faster button pressing during combos and move entry.
Shield Grabbing
The shield is a defensive tool that surrounds your character with a protective bubble to avoid harm. If an opponent gets too casual when hitting on your shield and strays up next to it, you can perform a grab from within your shield to toss him and begin attacking.
Projectile Baiting
Long-range projectiles don't only serve as a method of dealing damage at a distance. A steady stream of projectiles can bait an opponent into moving in to attack you which, if countered with proper timing, can leave him susceptible to a melee attack.
Versatility
While many beginning players prefer to select a character that they are comfortable with and stick with that character until they have mastered it, it pays to spend time working with a range of characters. Every player has its weaknesses, and knowing how to play multiple characters increases the likelihood you can capitalize on your opponents' weak spots.