it is certainly not something that I do routinely but I had a client a few years back.
What I have learned from him it the need for flexibility in approach. Not so much with the exercises but that the state of mind can be quite different from one time to the next, and I never quite knew into which of his realities I would step into when I saw him.
He did well with exercises that tapped into things he had done before. He had been an avid golfer, and his club became one of our exercise tools. I also found that he preferred repetition and predictability with exercises. It was not easy to introduce something new.
And that one thing you will need a lot of: PATIENCE.
I wish you good luck.