The technique is pretty simple. Get into a light trance, and build your ideal temple in your imagination. You can set it up any way you like, with whatever features you want. You’re only limited by your imagination. Try to do it at least once a day for a week or two because the astral is always in flux, so it will change around on you unless you make an effort to solidify it on your mind by visiting it regularly.
i think there is even a tutorial here on the forum if you try a search.