Ok, it is quite easy.
Make a macro /macro sit /sit
climb a ladder or pipe, and sit while on it. you now are in the air.
to move, just move forward, and then sit. as soon as you start to stand up again, use the macro to sit, and you stay at that position.
to get higher, roll forward.
if you have hacker loaded, you can attack anyone on the ground, as there is no distance limit downwards.
also use the healthbug if possible, and you are like a god in the air.
it is impossible to interlock you up there.
perfect for farming
