Magicians are trained to create an astral temple. The exercise is to imagine a place filled with the symbolism that you believe aligns the universe with the purpose/location of your temple. For instance, if the temple is in Yesod, a sephira associated with the moon, one may have nine pillars within an open air amphitheater. It may be on an island surrounded by water. The moon may hang in the sky permanently full. The altar may be covered with a purple cloth. This is a valuable exercise.
You are told that once you form this place, you can go there to perform magic. I suppose you can, if you are particularly good at forming a lasting place on the very fluid astral using nothing but your imagination and will.
The problem with it is two-fold. First, you have to visit that place very frequently. The reason for that is that the new magician's imagination is usually pretty weak. One is basically constructing the place afresh every time out. Secondly, what happens if you haven't been there a while? You have to stop and think. What did I build? What is there? Oh no, what did I put there? Do you have to do that when you go home every day? Likely not. Can you remember the layout of your first apartment even though you haven't been there in twenty years? Probably. Why does this happen? Those places are real. The temple you built is not. It does not exist anywhere but in your head. Deep down you know that and your temple is just one more thing you have to overcome in order to succeed. It should be said that particularly talented or sufficiently experienced folks can do this.
Did you ever wonder where this exercise came from?
I have no way of proving this but I think some magician understood his/her sense of place. Having a sense of place in this world is reflected in others, or vice versa. Having achieved a sense of presence here, I found my place on the astral. My place is in Yetzirah, the formative world. It is exactly where I need to be to do magick. My every talent converges on that place. I am fully at home there.
My place does not contain any false symbolism. In fact, in contains almost none of the symbolism I have been taught or read about. I did not imagine this place. I haven't added to anything that was there. Yet everything is alive with purpose. This is just as real as anyplace on earth. When I am present there, I am unstoppable.
I suppose there is another such place in Briah. From there, I would think the barest thought would create on this plane. Someday, I hope to find out.
Artificially creating an astral temple is a worthy effort. It should be understood that this is a temporary home at best. Find yourself and you will find a pre-existing place on the astral that yours.
How do you find yourself? Strip everything away. Everything. In all my years as a magician, I have never been satisfied when I successfully added something to my life with magick. Presence is achieved when there is nothing false left. Rid yourself of everything.