Figuring out how to help others achieve is on the list of those who succeed.
For me it wasn't one ritual/ceremony, it was a preparation of the self with first initiation starting a chain reaction that led to the Angel:
These preps can be put into two categories relative to the Angel:
Passive: Personal development
Active: Alignment with Angel
The active part began with initiation and creating a ritual for The Vision of the Holy Guardian Angel from a few books that were available*.
Yet, years before that was meditation practices, metaphysical theory, and ESP training**. Training which continues after initiation with introduction and adaptation to new realities and shed illusions.
Cultivating personal qualities like scientific inquiry(fallibilism) & spiritual dedication contributed to enduring and being able to process the event. Not to say there weren't some nasty bumps, it's fair to say that I barely survived the stresses involved with this method. But I did survive the success in having the hyperphysical experience and drawing coherent understanding from it for future work.
Timelines may vary for others but before the first initiation there was about 5 years prep. After initiation it was 13 years until contact, which was about a year of direct work with months in steady hyperphysical trance. Then it was about a decade of processing that raw experience into something coherent to communicate. Then once that's figured out there's doing something with that which is where things are at now for me and corresponds with establishing a school of thought.
*Mystical Qabalah; Complete Book of Spells, Ceremonies, and Magic; 777; Witches' Bible Compleat;
**Jane Roberts and the Seth books exercises leading to the True Dream from the Gates of Horn to align the self.