By the Red Asp, Hallin's Stand
It may seems obvious, but the key to practical invisibility is to be not-seen. What does it mean to be not-seen? Let us turn this around and ask: what does it mean to be seen?
To be seen means that the visible object has somehow attracted the attention of the viewer. Most of the time, you can count on a target's vision to slide across nineteen out of twenty objects without really seeing them, because to the target they simply make up part of the general background of his or her surroundings.
To be not-seen, you must become part of this general background. Lose your individuality and become an integral part of your surroundings. In this way, you may wear the cloak of shadows even upon the salt flats at noon.