You probably already know how to float around Dalaran with a parachute strapped to your back, but did you know you can take that parachute anywhere? If you can be summoned or hearth there, you can take this parachute there. What you need to do is adjust your height so that you are flying in a position where you could just as well be standing. Your mount will likely be half underground. Once you have that height, land when the restricted area debuff hits 0. With some luck you should have the Parachute buff that looks like a bag instead of a feather and lasts 1 minute. DON'T MOVE once you get this buff; hearth, take a portal, enter a BG/instance or be summoned and when you arrive at you destination, move along slightly sloped ground to enable the chute. Don't let any buffs on you fade on their own, right click them off as they may bring down your chute when they fade. Here is a little vid I made with this trick:
Why is this useful? This is a never-ending slowfall so it is great for non priests/mages on long jumps. Also useful to hide flags in PVP and looks pretty funny when stealthed.