To call upon those powers higher than yourself, you must first figure out who you are talking to.
If you wish to call upon the demonic powers of Lucifer’s tribe: you must repeat a certain phrase, called an “enn”. Every demon has a different enn, and wrongly enning is usually a mistake that costs you your life.
If you wish to call upon the magnificence of Jah’s former Archangels: you must send the correct angelic seal, and the failure to send the right sigil leads to a fate some consider worse than death.
After this, you may ask the entity one question. Keep in mind: if they do not know much of the subject, they will decline to answer. For example, time is Gusion’s main wheelhouse. He cannot help you raise somebody back from the dead, though. Take extra precaution in planning your question, cause you’ll only have one shot.