The Great Banshee Switch
From Halopedia, the Halo wiki
This stunt requires great skill, faultless timing, and sometimes just pure luck. It also requires the cooperation of two players (Player A, Player B).
To start the trick, both players must be flying in the same direction at the same speed. Person A must position his Banshee directly above Person B's Banshee, and just a few feet farther forward; the Banshees should be touching. Both players must then dismount their vehicles at the same time; when a player finds themselves sufficiently close to the other's Banshee, they should hold X (or RB in Halo 3) to enter the craft. If the maneuver is executed properly, the duo will have switched Banshees in mid-air.
A variation of this technique is useful when avoiding skyjacking. A player who is about to be boarded should barrel-roll upwards as they are about to be kicked out; their momentum will cause them to launch upwards when they are forcibly removed from the vehicle. The victim may then fall back down onto their Banshee; as they fall, they should hold the appropriate button to reclaim their Banshee. This is, however, easily countered; the attacker can simply boost once they gain control of the vehicle, causing the victim to fall to the ground (or their death) rather than landing on the Banshee.
Another variation may be practiced in Campaign. A player who finds themselves in a dogfight with a Banshee can execute the trick to hijack their opponent. It is difficult, however, to position a Banshee over an enemy Banshee, as the enemy Banshee will often flip and turn repeatedly in an attempt to target the would-be boarder. Landing on the target Banshee is difficult for the same reason.
Banshee Juggling is another trick that is similar in nature to The Great Banshee Switch. It requires two players (Person A and Person B) and one Banshee.
Person A should enter the Banshee and fly low over Person B. Person B should hijack the Banshee. A third of the way through the boarding animation, Person A should perform a backflip with the aircraft; this will cause A to be launched above the Banshee when they are ejected from it. Person A should, as they fall, re-board the Banshee. Person B should react as Person A had previously, performing a backflip when Person A gets a third of the way through the boarding animation. Assuming that both players are skilled enough, they may repeat the cycle endlessly.
When flying the Banshee in Halo 3, hold A and go forward. If done right, the Banshee will drop quickly straight down, belly-first. If a Banshee lands belly-first, then it will explode (and kill nearby enemies, if applicable), but the driver will sustain no damage. This is useful when being targeted with a Missile Pod, or in cases where the short-term benefit of a surprise attack may be worth more than the long-term benefit of a Banshee. Note, this is only possible when the Banshee has suffered an extreme amount of damage.