Evokation is calling an entity to you. unlike Invokation, drawing an entity to you, the being you evoke has a choice on whether or not to come. If it comes from being called, you can draw much more energy from them then if you bind them and force them to come. Normally, evoking an entity involves the knowledge of their name and a means of preventing them from invading your conciousness.
First Step is finding the name. This isn't very hard. A simple method would be just imagine the kind of being that you want. If you concentrate, the name will normally come to you.
Next you have to set up mental barriers. You can imagine a wall around your conciousness, visualize this, feel the walls, and generally your mind will channel energy into a barrier around itself. Depending on what type of being you are evoking, you may need to add extra barriers or even use a pentacle.
Next is the actual calling. You will find a ton of incantations, chants and spells for this, but the simplest is just calling the name, mentally, three times. Since most entities that can be invoked will not exist in the material, the time it takes for them to travel to you should be small, two minutes at most.You will know if the being chose to come because you will feel their presence.
Its hard to describe what a presence feels like. You might feel like someone's watching you, or as if there is something always behind you. The most obvious indicatior is if they attempt to break into your mind. You will feel a panic, as well as a force pressing at your skull. Concentrate on a single thing if you can, or try to push the being out. If it doesn't let up, banish the entity at once. If you can, however, placate it and attempt to commune with it.
Always try to study an entity before calling it. If you cannot find any information, give up and try to find a different entity. Always meditate before calling.
I always thought invocation is drawing energy into yourself or from inside yourself while evocation is drawing energy from outside yourself and and using it without taking it into yourself. I am an expierenced eclectic older witch.
I've always been taught that evocation is calling up and out from within while invocation is calling up and in from without. Entities are never forced by your side, they always have choices.
Now, there seems to be a mix up between what is being firm with a spirit and what is 'controlling' a spirit. In a Wiccan's circle, for example, deities and elementals are invited. When it's time for them to leave, the deities are generally asked to leave politely while the elementals are told firmly to leave. This is not disrespecting the elementals if you do it tactfully, and is not in any way having authority over them.
As for using pentacles, that may not be the best idea to use them as a barrier. Pentacles are often used as a channel of energy and the tie to the physical world within a Circle. It's said that they attract energy and attention within the subtle planes. For those who don't want to call such attention, they use what is called an elemental sphere that has the four sacred directions while spirit is in the center.
For barriers you can use wards if you'd like. The definition a ward that I have come to learn is that it is a temporary, though higher concentrated shield. The easiest way to cast a ward would be to intend a wall or different archetype in front or around you. If you want to go more complicated, you can use sigils, incantations, visualizations, charms, talismans, and the like.
Evocation is to call outside of the circle, often into a triangle of Art (Triangles three sides Representative of manifestation on the Physical, Mental and Astral planes via names of god and ruler of that plane) Invokation is to take into your body or yourself. according to the practices of ceremonial magick.
In short
Invoaction is INTERNAL
Evocation is EXTERNAL
You need more than this to perform a proper and safe Evocation...
The entity might come but its unlikely and depends on who you call, This is just likely to give delusions or create a thoughtform...
A wand should be needed to give your status apparancy, and an Athame to represent your dominacy incase it turns hostile...
You shouldn't need tools, and an athame is not to represent dominence. In some ceremonial traditions, there is use of a sword to combat and fend off certain spirits, but the only people that use swords as athames are newer traditions who use it in a group setting so all can see.
As EisKora said, a Athame isn't a weapon or used to symbolize dominance. It is a toll that represents the element of fire (I think, correct me if I'm wrong). It is used for casting circles, channeling energy and in some protection rituals where you need to draw symbols (such as The Lesser Banishing Ritual of the Pentacle).
No you don't need tools, a lot of the time but you need more than what has been given here and using tools shows more respect of the entity...
The Blade symbolises Air to me, but there is disagreement regarding wand and Athame/Sword...The Athame can represent dominance, although maybe that wasn't the best word for it your right there. I would say it represents the strength of the magician, hence the usage of it when dealing with more...Hostile entities. I would use a wand when dealing with a friendly/Neutral entity, and a bladed tool with a hostile entity. But then its generally down to personal association.
This isn't enough for the basics of evoacation in my eyes though...
