I didn’t actually say ‘evoke’, I said ‘summon’.
Evocation is bringing an entity into physical manifestation in your physical temple. This is not a physical space so I don’t see that as being the right term.
It’s more like a place in the lower astral. It may be what some call ‘the crossroads’, but I don’t really use that concept so I can’t say.
So, go to the space, if it helps visualise a circle, or call the entity as you would normally, but as that presence come you should get spontaneous visions in your minds eye in this space, of what they look like. I usually see them walking out of the dark into the space near me, which is lit with no apparent light source but I ‘see’ them anyway.
Yes I think you are in some level of trance - i.e.a state of altered consciousness - to get there in the first place. As you close your eyes, forget your surroundings and focus your mind fully in a visualisation like this or any other kind, you are altering your consciousness. Keep concentrating and the deeper into trance you go the more real the place feels and the more into focus it comes.
Can you make an invocation before ???
If you like. Or during. I mean, it’s your ritual. I wold say try it both ways and see what you like. the best magik is personal - don’t use other people’s formulas, just get ideas, then play around with these things and work out what suits you.
We’re all different with different and complicated energy systems, so what works for some doesn’t always work for others, that’s normal. Hence you have to just try stuff and figure yourself out bit by bit.