The form of the circle is not always one and the same; it is according to the
order of the Spirits that are to be called, their places, times, days and hours.
Before making a Circle, it ought to be considered in what time of the year, what
day, and what hour, that you make the Circle; what Spirits you would call, to
what Star and Region they do belong, and what funcions they have. When the
Circle is finished, you shall proceed.
A magic circle for all conjurations (16th century):

Example of another magick circle:

Example of a magick circle from the Goetia, with the magick triangle outside of the circle in which the spirit should appear:
