I saw this on another board and decided to ask about it here. I'm also going to include my response, but I'd like to see what other people have to say as well. For the purposes of this post, I'm going to explain the terminology I use so that, hopefully, this thread will discuss how to teach jump/flying kicks instead of what "midair", "jump", and "flying" really mean. 
Mid-air: jump straight up off both feet, kick in the air; kick can be with either foot
Jump: jump off one foot while driving the other foot into the air to gain height/momentum; kick can be with either foot
Flying: a jump kick done after more than one step
Generally, I start teaching jump kicks with front kick, although the same general sequence can be adapted as needed for other kicks; once a student understands how to perform jump kicks, the initial steps can be left out, and students can be taught to modify the jump kicks they already know to accommodate differences in foot, hip, and body positioning, as well as stepping and jumping, necessary to perform other kicks.
First I teach them how to jump - for mid-air kicks, how to jump off both feet, which, for many of them, is quite difficult. When possible, I use a mini-trampoline, as many students are afraid to jump and lift both feet, because they are afraid they can't land; using a mini-tramp allows them to jump higher, giving them more time to adjust their foot position for the landing. Once students can jump off both feet, I add a lead leg kick. Once students are comfortable with lead leg kicks, I introduce rear leg kicks. Generally, I teach mid-air kicks before flying kicks, because many students find them less complex, because their is no stepping.
For flying kicks, I generally start with stepping kicks - for example, to teach flying front kick, I might start with front kick, step, front kick, where both kicks are done with the same (rear) leg, then change the step to a jump, then omit the first kick, leaving the step flying kick, after which students can begin to work on taking more steps and learning distancing.
To teach students to jump higher and/or retract their non-kicking leg (many students jump high enough, but trail the non-kicking leg - usually for landing purposes - so much that it looks like they're not as far off the ground as they really are) I will use a series of obstacles - small pads, tumbling mats, and belts held at various heights by students. For students who jump but don't move forward, I will set up a kicking target - usually a Wavemaster or Bob - behind a height obstacle such as a belt, to give students a visual target, which is often easier for students than just a target (don't get off the ground), just a height obstacle (don't move forward enough) or no target (nothing to visualize).
Whenever possible, I also have students perform all new kicks - especially jumps, because they're so hard to watch yourself while in progress, in front of mirrors, and occasionally I'll use a video camera to give them more feedback. Swimming pools are also good places to teach jump kicks; in the pool, there's plenty of hang time, while off the side or diving board (if the pool is deep enough) if you miss the landing, you're not going to hurt yourself.
Mid-air: jump straight up off both feet, kick in the air; kick can be with either foot
Jump: jump off one foot while driving the other foot into the air to gain height/momentum; kick can be with either foot
Flying: a jump kick done after more than one step
Generally, I start teaching jump kicks with front kick, although the same general sequence can be adapted as needed for other kicks; once a student understands how to perform jump kicks, the initial steps can be left out, and students can be taught to modify the jump kicks they already know to accommodate differences in foot, hip, and body positioning, as well as stepping and jumping, necessary to perform other kicks.
First I teach them how to jump - for mid-air kicks, how to jump off both feet, which, for many of them, is quite difficult. When possible, I use a mini-trampoline, as many students are afraid to jump and lift both feet, because they are afraid they can't land; using a mini-tramp allows them to jump higher, giving them more time to adjust their foot position for the landing. Once students can jump off both feet, I add a lead leg kick. Once students are comfortable with lead leg kicks, I introduce rear leg kicks. Generally, I teach mid-air kicks before flying kicks, because many students find them less complex, because their is no stepping.
For flying kicks, I generally start with stepping kicks - for example, to teach flying front kick, I might start with front kick, step, front kick, where both kicks are done with the same (rear) leg, then change the step to a jump, then omit the first kick, leaving the step flying kick, after which students can begin to work on taking more steps and learning distancing.
To teach students to jump higher and/or retract their non-kicking leg (many students jump high enough, but trail the non-kicking leg - usually for landing purposes - so much that it looks like they're not as far off the ground as they really are) I will use a series of obstacles - small pads, tumbling mats, and belts held at various heights by students. For students who jump but don't move forward, I will set up a kicking target - usually a Wavemaster or Bob - behind a height obstacle such as a belt, to give students a visual target, which is often easier for students than just a target (don't get off the ground), just a height obstacle (don't move forward enough) or no target (nothing to visualize).
Whenever possible, I also have students perform all new kicks - especially jumps, because they're so hard to watch yourself while in progress, in front of mirrors, and occasionally I'll use a video camera to give them more feedback. Swimming pools are also good places to teach jump kicks; in the pool, there's plenty of hang time, while off the side or diving board (if the pool is deep enough) if you miss the landing, you're not going to hurt yourself.
