For me, it was my first time. Initially, I wanted to do this for my rush/stress issues at work. I had also been in a 'spiritual' process for a while and felt that this needed to happen.
Anyway, the trip. It was a very intense start, during which my body/mind system had to work its way through dark layers. A lot of nausea and feverish tunnel-like layers that my body had to pass through. All emotions/blockages in the subconscious were being lived through simultaneously in the present moment. It seemed as if everything had to be magnified so that it could be processed and disappear from the system.
The next level was the existential question of who I really am. This was very confusing, with my consciousness being shapelifted from dimension to dimension. 'Dark' influences also came into play here, likely wanting to hold it back. Even Marcel was used for this. Sorry Marcel 🙂 Maybe it's due to my background that it went this way. Or perhaps movies that got stuck in the subconscious.
Eventually, the little self broke free from duality and ended up in spheres like the unground, about which not a word can be spoken. Absolute nothing and everything at the same time, if I must give it a reference. I felt that from here you can discover even deeper layers and wisdom. Noticed that only concentration and other influences threw a spanner in the works.
All in all, almost a week has passed. Living everything in slow motion and with understanding for everything that happens from a consciousness of wholeness, with little sense of time. Work went well too. Living in the moment and situations are presented to me when I think of something.
Tips I can offer: Make sure your intention is clear beforehand. The environment and setting are also important. Music, scents, etc. These are factors that can disrupt the trip if you are very deep. At least, that was my experience.