They're those feathered beauties plastered to your shoulder blades that magically sprout forth from the twisting aether once you have ascended past level ten. Apparently, you had them all along and just forgot they were there, which is understandable because when they're not in use they're nowhere to be seen. Here a few tips, tricks, and musings that can help you, the blossoming little Daeva that you are, keep from tumbling out of the nest and landing flat on your face.
Your wings are obviously one of the selling points of the game, and as such, it's advisable to get as comfortable with the controls as humanly possible so that you too can take to the skies and dogfight with the best of them. The controls, predictably, are quite customizable and you, the industrious tweaker that we all know you are, should feel more than welcome to change them completely. Page Up and Page Down are the default key bindings for take offs and landings and R & F are the defaults for rise and fall. From the moment I started playing the game I felt that rise and fall were much more fluid if done with the mouse alone by holding down the right mouse key, something the tutorials made no attempt to mention. Therefore, I switched around those two key bindings and now take off with R and land with F and have basically discarded the rise and fall bindings.
Obviously, anyone with wings is going to be more than tempted to BASE jump from any structure more than sixteen inches from the ground. This is all fine and dandy, but there's one oddity that needs to be mentioned so you don't end up a hapless crater to be urinated in by Plumas. If you choose to glide while free falling you cannot switch to open flight without first free falling again. What this means, in layman's terms, is that if you leap from Elten Fortress like a balls-to-the-wall daredevil and choose to glide instead of fly, you cannot just automatically switch to free-flight mode. Now, this isn't a huge issue in and of itself, but coupled with inadvertently slapping the space bar less than ten seconds (the cool down for any type of flying, be it free-flight or gliding) after you first hit space to glide, you will begin to uncontrollably free fall until you slam into the ground, and it, in all likelihood, will hurt.
Another small and helpful trick is that if you find yourself pretty far from the ground with the knowledge that you're not going to be able to land before running out of flight time, it's advisable to just admit defeat and fold your wings so you can free fall for a few seconds to regenerate flight time so, if properly timed, you can engage glide inches from the ground and touch down unscathed. I say inches, but really, if you try and time it that close, you will undoubtedly still seriously injure yourself due to lag. The ten second cool down for flying also plays a factor here.
Gliding is a very powerful tool if utilized correctly. If not utilized correctly, you may just end up looking like a fool. A lot of the zones are built in such a way that, with enough investigation and ingenuity, a talented Daeva can learn to cut their travel time tenfold. Like in Sanctum, when you miss the transport and just leap off the dock to glide down to it, without the hassle of waiting for another boat. Also, just south of Pilgrims' Respite in Verteron there is a large rock (it's rather hard to miss) that can be used as a great jump point to easily glide the entire distance down into the holy ground. There is another spot just north of the Respite: a cliff (Altamia Ridge) overlooking the Frillneck Habitat. From there, you can glide almost the entire distance to Tolbas Village with the use of a flight time potion or two. This is also a good example of a flight that you need to be extra careful you don't plummet to your doom by running out of flight time a few hundred feet from the ground. Not that I'm speaking from personal experience or anything. As a slight side note, there are a lot of environments that look explorable that aren't mapped. I was never adventurous enough to dive into them, but I'm sure there might be a troll village dancing their little heads off down there somewhere.
The only real disadvantage to gliding down a great incline is the realization that what comes down must also come up a lot of the time. And sadly, there is not currently an easy way to glide up an incline, as splendid as that would be. Another slight suggestion, or observation, is that the animation for free falling is that of you ridiculously flailing about. It would be nice if, while free falling with unused flight time, you were more gracefully diving with the confidence that you would, at just the right time, sprout your wings magnificently.
Aion's wings, at first, may just seem like a cool novelty, but they are a versatile and useful appendage that can make travel in a mount-less game much more bearable, especially as you discover new and awesome ways in which to use them. There are obviously dozens of facets I left untouched about flying in Aion, such as PvP and itemization, neither of which I had much experience with during the closed beta weekends. But, I think these are some good preliminary ideas to help get you off the ground.