Honestly, I don't really have any hard rules.
If I'm reading in person I usually let the other person shuffle, mostly so they feel more connected to the process-not because it has to be that way.
I do have habits, like shuffling and cutting the same way every time out of muscle memory, but that's about it. I don't mind if people touch my cards, I don't do rituals before or after readings, and I don't store my decks in any special way.
I've been working with tarot for around 10 years and have kept things loose and intuitive. No fixed structure-just whatever feels right in the moment.
Loved your post, can't wait to see what others share too!