I learned to get into the required state through active meditation.
In other words, I was performing a meditation exercise like imagining a certain color of candle burning and allowing the impressions from it to come to me.
At a certain point, I lost track of my physical body and all sense of time.
From time to time, I would end up somewhere else. I just flowed with it and allowed the experience to unfold.
As I practiced the meditations more, I found I could reach that state much more easily and quickly.
To get into a light trance state for mental communication, I just do this:
(1) Center myself with three cleansing breaths.
(2) Relax and soften my gaze.
(3) Intone the name of the spirit I wish to connect with over and over until “it feels right”.
(4) Say the spirit’s name and “Come to me! Settle in close to me so that our communication is strong and clear.”
Those are the basics.
During ritual work, I also use a bowl of water or fire as a gateway and sigils to focus on.
Then when I feel the time is right, I call the spirit to come. I close my eyes and allow my imagination to see what it will see.
Sometimes the sigil appears as a gateway in my mind. Sometimes I see the spirit walking across an open grassy field walking toward me beneath the full moon. Sometimes I’m in a desert under the burning sun.
The important part is to allow it to unfold and to “play with it” to get your conscious or “critical” mind out of the way.
I personally feel the spirit “pop through” the gateway and settle in deeply around me. I usually feel it as pressure and vibration in my crown chakra, the back of my head, the tops of my shoulders, and my upper back.