The following are some helpful tips for preparing to perform the Opening of the Key divination.
If possible, perform the divination in a calm frame of mind. But acknowledging one’s feelings is better than attempting to deny them. Better to admit “I know what I hope the result of this reading will be; now having acknowledged that, let me see what it actually is.“
You may wear or wield any magical attire, insignia, tools, etc. in addition to the Tarot deck itself, which will assist you to be free from undesired influences and to receive appropriate guidance in manipulating and interpreting the cards.
You may wish to make invoking pentagrams, hexagrams, or other symbols over the deck before beginning, calling upon whatever elemental, planetary, or other forces are appropriate for you and for the reading.
A sample invocation is given below as “The Invocation”; it is the example the Golden Dawn themselves suggested. You may find it too “theistic” for your tastes or worldview.
Hold the cards in the left hand, or place them on the table with your left hand on the deck, and holding a wand or other suitable instrument in the right hand, invoke thus:
In the divine name IAO, I invoke the great angel HRU who is set over the operations of this Secret Wisdom. Lay thy hand invisibly upon these consecrated cards of Art, that thereby I may obtain true knowledge of hidden things, to the glory of thine ineffable name. So mote it be.
When you have finished any preparations or invocations you wish to perform, you can proceed to the First Operation.