By keeping a salt shaker full of flour in one’s pocket and sprinkling the flour in the air, one can tell if there is a breeze and in which direction the air currents are moving.  This simple trick can potentially save one from having to remove paint overspray from several vehicles in the path of a possible overspray event.  Hunters often  have used this same method to remain upwind from their target.

As they say, “A ounce of prevention is worth a pound of cure”.