A long time ago I jotted this down in a notebook, the author unknown due to my tendency at that time in my life to overlook little matters such as that.
Get a raven or a crow’s heart, split it open with your athame; make three cuts and place a black bean in each cut. Plant it, and when the beans sprout put one in in a pouch hung about your neck and say–
By virtue of Blackbird’s heart,
And by strength of my great art,
I desire to be invisible… and forgettable.
So mote it be.
And so it will be as long as the bean is kept around your neck, and until the next full moon. Be aware though, this invisibility is not one in which light is refracted and you cannot be seen. It is one of glamour in which people will tend to “not notice you.” You will be less conspicuous and the memory of those who have seen you will be somewhat foggy and unclear.