(Warning: this is a long thread. It is intended for beginners, but even adept can benefit from it)
Through out my spiritual practice. From energy work, sigil magic, to evocation and invocation. I realized the key components of what almost guarantees a successful working. Although, through my time here in BALG and other occult sites, I saw a huge concentration on evocation guides rather than invocation. So, I felt the need to make a post about this and to clarify lots of misconceptions on the process. Indeed, these evocation guides were highly focused on steps and tools. I am not trying to talk wrongly or look badly on the authors of these guides. Since they are purely trying to help and shed some light from their on perspective and experience in the practice. Nevertheless, I am also not trying to make it seem as if I am coming up with new ways of invocation but merely shedding some of my on light on the subject and its reasons.
In the beginning, I am just going to explain briefly the process of invoking a spirit. Invocation is not POSSESSION and please those who say it is, its not. Invocation is the process of calling out to an energy (spirit) into your own consciousness. Wherein possession, the spirit, is taking over your body and mind, which comes from the doctrine of religion. So, why would you consider invoking instead of evoking? Invocation leads the operator to inherit some of the qualities of the invoked energy (spirit). That is the reason why many practitioners, seek invocation rather than evocation. That is also besides the time consuming part of evocation.
So… what is it that you are trying to shed some light on?
In short, intention and attention. What do I mean by that? Well, I am going to describe below on of the ways practitioners use to invoke a said spirit. However, through that process I will be explaining to you what many has missed in terms of emphasizing intention and attention.
Tools you can use (which you do not need - unless you are a beginner);
- Sigil
- Incense
- Candles
- Enn
- Water
LHP method:
Set the candles in a shape of triangle which is thought of as a portal between realms. Within these candles, you are to set the sigil of the spirit. On the left of the sigil, you are to set the water. On the right side of the sigil, you are to set the incense. That is in short the tools and its placement. You may be wondering why is everything set in that matter. Well, this goes back to the elements and it directions. West = water, North = fire (candles), East = Air (incense), South = Earth (sigil can be thought of earth because its written on paper which come from earth) and if u do not like that example, your own self is soil (earth) 
.
Okay with that now explained, allow me to clarify few things that makes so many unable to achieve a successful invocation, even if they made successful contact they wont be able to experience it and think that its their senses. No its not your senses, its YOU. Want to know why? keep reading.
It is said that after placing your tools and creating this portal and its pillars with intent. Some like to state the following while placing the tools: with the candles being let, I am opening the gates of fire (or opening a link between the realms), and so on to each item and its significant.
Moving back to the point, Now, You are to gaze and relax on the sigil. However, what so many have failed to say is state your intention.
One way I personally use to reinforce my intent is by stating in my mind or out-loud my intent; By gazing at the sigil I am connecting to (spirit name). Then, your attention needs to be focused on your intention while gazing.
Next point is the litany or Enn. Some do not like to use Enns and choose to make their on litany for the spirit that includes their name, rank, attributes. To me they come from a religious doctrine and one way of worship so i do not like to use it. However, this is a small example:
“Spirit I call you forth
O great king of bla bla bla, I call you forth.
Spirit I invoke you
Spirit come and descend upon me”
You get the point, so I am not going to dive deeper in this because you can create your own, or just use Enns. Either way its up to you, but I recommend using the enn since its directly linked to the energy frequency of the spirit. And this is the second point in what many has failed to demonstrate. You are not supposed to just read it or say it 81 times or 108 and kboom your spirit is there. Although these numbers has their own significance but are not needed for your simple invocation. Since i see many and including myself in the beginning being lost counting how many times or focusing on how long left for them to reach their number than falling into trance.
So, how should you use the Enns most effectively?
In short? Vibrate them. Logically by gazing at the sigil you are slowly falling into trance and intending to create a connection with a spirit. By chanting the Enn and VIBRATING it, you are building that energy frequency to be able to perceive the spirit, which why there is different enns and not just one magical words and tara here is ur jenni 
Allow me to prove that to you. if you take a chakra meditation lesson, you are asked to vibrate certain words. Why? These words hold vibrational energy that stimulate certain chakras and open it up. I am not going to any further on chakras because i do not seek to confuse topics. Moreover, I am not a scientist to really explain this, but if you do a little research; You will understand that sound is not more than vibrational frequencies that our minds process and make words and meaning off. Going back to the point, when you are vibrating the Enn, you are opening up your consciousness to that frequency of the spirit’s.
Now since you have gazed and chanted properly. Throw your intention once again, and you can do that by simply saying something like “spirit I ask that you come, I invoke spirit name” and bring your attention to your senses, try to perceive. Do not set time, or push, or try because by that you are not focusing your attention, your are actually thinking which is why meditation is important.
Now if you have not seen the spirit or heard due to your senses you can believe that, and start working on them.
But, for the sake of the this guide, state your desire and thank the spirit for its aid. You can thank the spirit by offering it something or stating that alone. You can also tell the spirit that you are going to give them a gratitude after job well done. In this point you are to dismiss the spirit or give them the freedom to leave when they wish out of respect (trust me, they got more important stuff to do than you, so they will leave right away).
At a certain point in this thread i was so struggling not to fall or get sucked into details because i know there are other guides that shows the whole boring detailed process with extra information that is not needed.
Note: the whole process is similar if not the same as evocation. The only difference is you, setting you intention and attention to the right place. You may kind of disagree with me but once you master evocation you will understand what I meant here.
