Self-Exploration
There are several resources that can be used for self-exploration. I do not recommend any of them as definitive. They are simply the best resources I know of at this time. There are many providers and one must be careful with any service selected. The ones listed here are in some way connected with professional organizations.
Mediums
The Windbridge Institute is a scientifically oriented, ethical group that certifies mediums through a rigorous process. They can be contacted at https://www.windbridge.org/ Mediums certified by the Institute can be found here: https://www.windbridge.org/mediums/
Past Life Regression
There many hypnotists who offer this service. The Newton Institute screens and offers credentials to trained therapists. https://www.newtoninstitute.org/ A list of the members of the institute can be found here: https://www.newtoninstitute.org/full-member-list/
Mirror Gazing
In Reunions: Visionary Encounters With Departed Loved Ones, Moody (1994) discusses the Psychomanteum. A room specifically designed for contacting deceased relatives. Instructions are presented for the procures to be used and for the development of a room to be used. Greyson (1996) reviews the book and states there may be some unintended consequences from experimentation with this technique.
Self Hypnosis
The best introduction to Self-hypnosis, what it is and what you can do with it was written for the average person by Lecron (1964).
Powell (2009) presents an excellent systematic introduction to self-hypnosis in a guided workshop format (with CD). This is possibly one of the best ways to learn the technique.
After the technique learned use it to descend an elevator, cross the lawn, and walk up the stairs to an art museum. In the museum, you approach a painting. Gaze at the painting and you will see aspects of a former life. One of the interesting aspects is that upon return to the museum you may not see the same scene. Are these elements of a past life. This is unknown until such times as you can verify the information. I have found this to be the most useful of all the available techniques.
References
Beischel, J. (2021). https://www.windbridge.org/
Greyson, B. (1996) Book review of Reunions Visionary Encounters With Departed Loved Ones. J of Near-Death Studies, 14 (4) 281 – 286.
Lecron, L. (1964). Self Hypnosis: The Techniques and Its Use in Daily Living. NJ: Prentice-Hall.
Moody, R, and Perry, P (1994). Reunions Visionary Encounters With Departed Loved Ones. NY: Bantum Books.
Newton, M (2021). https://www.newtoninstitute.org/
Powell, C. (2009) Self-Hypnosis: You Can Change Your Life. London: Connections Book Pub. Ltd. (with CD)