There are many different methods of a invocation etc. I found some useful info and hopes this helps.
Invocation is when you want that particular entity to step into your body, and you become them, and you absorb those particular energies. In many covens, different pagans will call in a particular quarter, and, when they do, they become that quarter, absorbing that particular energy so much so that they become that Quarter. They then have to stand at that Quarter and guard it, as they are the actual Guardian of that direction. It is interesting but several covens have "words of wisdom" wherein say a pagan, who has invoked a particular Quarter then speaks of wisdom of that element, as the Element is actually speaking through them. The same would be if you invoke the Goddess.
When one draws down the Moon, they are invoking the Goddess into them, and then they are the Goddess. Many of your Wiccan covens say only a male can invoke the Goddess into a female. This is not true. This is solely an idea of Gerald Gardner for male to not only participate in coven rituals but to have some control, when in all actuality, you need no one but yourself to call Her into you. Long ago, when a Witch stood out alone under the bright shining Moon, it was she, the Witch, who called the Moon into herself. Her and her alone.
Invoking and invocation are two different things. To invoke a god is to call upon or ask for the presents of said spirit. Invocation is the act of possession of the god it is also refereed to as aspecting. This is because you are taking a part of the god inside you. There are many ways to invoke a spirit the easiest one being through prayer. Invocation of a spirit however, usually requires a ritual of some form. I suggest reading up on the gods you would like to invoke into your life. Just understanding their personalities can help you learn to invoke them.
