Out of all four nations, the Air Nomads still remain the most mysterious, given that we've seen the least of their culture in action. In The Legend of Korra, a new generation of Air Nomads have stepped up to combat injustice in every corner of the world, but that doesn't erase the influence of the original Air Nomads that came before them.
With the efforts of Aang and Tenzin, as well as Korra's decision to leave the spirit portals open, this beautiful culture didn't die out, so we've seen enough Airbending techniques to truly identify which ones took our breath away, literally and figuratively.
Breath of Wind
Naturally, it would make sense that most Airbenders would have strong lungs after spending the majority of their lives in temples high above the clouds. This increased lung capacity allows them to bend vast amounts of air by just breathing.
After Aang was first captured and brought onto Zuko's ship, even with his hands tied behind his back, all it took was a single breath to knock out the Fire Nation soldier behind him, ensuring a successful escape. He's also used this technique to magnify the strength of his bison whistle so that Appa and other animals can hear his call from miles away.
Heat Regulation
At the start of Avatar: The Last Airbender, fans wondered why Aang was perfectly fine wearing his thin Air Nomad garb while Sokka and Katara were bundled up in heavy coats. As it turns out, Airbenders have the ability to warm their bodies with instinctive breathing techniques that are a byproduct of becoming an Airbending master.
It may not seem like much, but this technique allows Airbenders to fight without the need for heavy winter clothes that would hinder their Airbending.
Enhanced Speed and Agility
Aang has demonstrated his impressive speed several times, often running so fast that he's stirred up tornadoes and strong winds. Toph constantly referred to him as "Twinkle Toes" due to his light step that often made it so difficult for Firebenders to get a solid hit in on him.
Most famously, fans remember seeing Aang's heightened agility in action after he humiliated a young Fire Nation schoolboy, effortlessly dodging all of the boy's punches until he tired himself out. This fits right into the Air Nomads' core values, enabling them to avoid violent confrontations in ways that Waterbenders, Firebenders, and Earthbenders could never hope to.
Air Scooter
Before they can be considered a master, every Airbender must create their own Airbending move. Aang came up with the Air Scooter, which allowed him to create a sphere of revolving air that he could ride around on, hands-free!
Not only does this technique allow him to travel vast distances without expending any energy, but the Air Scooter can also be used to effortlessly ride up vertical surfaces. As we've seen in Aang's flashbacks, multiple Airbenders can even use their own Air Scooters to make playtime a lot more fun!
Air Sphere
Aang can effortlessly create a sphere of air to protect himself or others from harm. During both times in his life when he was caught in a storm while riding Appa, he was able to generate an Air Sphere to prevent himself (and other passengers) from being separated from his beloved flying bison, even enabling Appa to fly underwater in the episode entitled "The Storm".
During his battle with Ozai, he surrounded himself in a sphere of air that enabled him to hover through the air at high speeds while simultaneously generating enough wind to propel Ozai and any of his fire blasts. Fans will also remember that during their fights with Vaatu, both Wan and Korra trapped the dark spirit in air spheres as the first step to sealing him in his eternal prison.
Spiritual Projection
The Air Nomads were the most spiritual out of all four nations. They rejected material pleasures in exchange for simpler lifestyles that encouraged a connection to the Spirit World. So far, Jinora is the only Airbender we've seen who's been able to spirit project. While there's still a lot of mystery surrounding this technique, from what has been shown in The Legend of Korra, it allows its user to separate their spirit from their physical body in order to communicate with spiritually-sensitive individuals while also enabling their spirit to travel through walls and other solid objects.
To pull this technique off, a bender needs a very strong spiritual connection, and only someone with an Airbender's discipline could have the gall to even attempt to separate their spirit from their body.
Air Bomb
Aang has utilized this technique frequently when performing hard landings to completely decimate his surroundings after a lengthy fall.
By slamming his staff or fists onto the ground, Airbenders can generate enough force to blow everything in their surroundings away, showing just how powerful they can be when they utilize one of nature's most unavoidable forces in an offensive manner.
Flight
Though they're constantly surrounded by animals who can take flight at any time (like flying lemurs and flying bison), Airbenders are unable to fly without the aid of a glider. At least, that's what fans thought until they watched The Legend of Korra.
Zaheer was an Airbending enthusiast years before he actually gained the power to bend air, studying the teachings of the ancient Airbender Guru Laghima, who was able to fly after freeing himself from all earthly tethers. Zaheer was able to do the same after the death of his lover, P'Li, taking to the skies in a way that even Aang wouldn't be able to replicate. With this skill under his belt, there aren't many places he can't go, and being able to take to the skies during battle made him difficult to attack and flee from. Unfortunately, this ability is wasted, since Zaheer spends his days chained to the floor in prison.
Although he can still levitate for the rest of his days, he won't be able to feel the open air through his locks anytime soon.
Air Blast
Just like Firebenders, Airbenders can kick or punch to release bursts of air that force their opponents back or shatter incoming projectiles.
Conjuring basic air blasts is definitely one of the most basic Airbending techniques, but it serves a wide range of purposes, making it a go-to move that's suitable for any situation, whether an Airbender needs to split some rocks, push back an opponent or two, or topple an entire mecha suit.
Suffocation
Because the Air Nomads shunned violence, Aang and other Airbenders never really used their bending to cause harm to others, but to defend themselves. After Zaheer gained the ability to Airbend in The Legend of Korra, fans saw just how lethal Airbending could be when it landed in the wrong hands.
Zaheer used his newfound powers to suffocate the Earth Queen, killing her in seconds. Not only was it frightening that he was able to do so from a distance, but the realization that this attack was unblockable was just as chilling.
If every Airbender were prepared to use their powers the way Zaheer was, something tells us the Fire Nation would've lost the Hundred Year War the moment they attempted to rid the world of Airbenders.