Right now just by thinking about it, but back then there were steps to make the movements easier.
In the orders they used something called tatvvas.
https://en.wikipedia.org/wiki/TattvaOne for each of the elements, going is made by projecting through them. However there is a trick to it.
The way I view it now is that there are a few reasons for the "extra" step that I will explain below.
The idea is that instead of using the image itself we will "invert" it. Two reasons for that. One is that if we look at Spirit as the life that goes on through everything, that is its Yang(or Dynamic) aspect. However it also has Yin aspect, that is the recording aspect. Active aspect of spirit lives, receiving aspect of spirit imprints.
To access that we invert the normal way of entrance/image.
Another reason will explain after the technique itself, since it won't make much sense before.
So what do we do. Akashas image is the black egg from the tatvvas below(image if from wikipedia):

What they did(and still do) is make that image on a white piece of paper.
So we have black egg on white paper. Take another piece, this time of black paper.
The technique starts by looking at the black egg for 2-3 minutes without moving the eyes as much as possible. Then looking at the black paper. In there there will be the shape of the egg, but this time it will be white.
This is connected to how the eyes work, I think. They adjust if there is one clear and consistent color, so when we look at the opposite we get the inverted form. Nothing esoteric by itself, the part that is important is that the second egg isn't just inverted but is also made by us.
It doesn't exist in the "shared" reality it exist only in the info that gets to our brain. In that way there is the idea that when we create it it has properties that the egg on the paper doesn't.
Here we get to the other reason why this step may be needed for some people. All projection by default happen within us. We don't travel "out there", we travel within and that mirrors the universe around us. For that switch to happen(from the egg we see in the paper to accessing Akasha imprint/record within us) we need a switch from something in the real world becoming something created by us.
Last step is just to project through the white egg. In the simplest form that would be to imagine you step through it like moving through a door and see where it will lead. Depending on belief system and other factors different people will be able to get different info and access, or none at all.
So in more simplified form.
- We take piece of paper, white background with the black egg on it.
- Hold it in one hand with black piece of paper in the other.
- Look at the egg for 2-3 minutes without moving eyes.
- Look to the black piece of paper. It would create the same form in the complimentary color, if that doesn't happen need either to look at it longer or to be more aware of movement in the eyes. This specific step is physiological, so it should happen right away for most people.
- Image you move through the white egg created by your eyes as if moving through a portal and observe what happens.
As most of these things go, how much can be observed, remembered and accessed would depend on different factors like belief system and other stuff. : )
This isn't "occult"(as hidden) technique btw, there are books that explain it and it was used in the orders in the first part of last century, although back then it was as most of what they did was. Although I don't remember name of books, but since the whole system back then was published by Regardie it's more or less clear that it is out there somewhere.