All I can say, is very basic and simple techniques of critical thinking, are incredibly powerful.
Its as if we are mini-scientists, trying to figure things out. Using some basic tools of critical thinking might be like a little hammer and chisel. You tap tap tap, and before you know it, an entire boulder splits wide open.
So its not really complicated.
For example, Reiki.
One would first do some basic research, and find out that its a type of alleged "energy healing".
Its as simple as, what is the PROOF that it works,or not?
And the proof has to be based on objective evidence and not anecdotes or stories, and controlling for the placebo effect, etc.
This moves into the basics of scientific method, which unfortunately most people never learn.
That's why that book the Demon Haunted World by Carl Sagan is terrific, that is what it teaches, how to think for yourself.
Its as simple as, what is the evidence for a claim? But people seem to get duped sometimes that stories are evidence, when they are not. If people start believing things without proof, you can get trapped in the rabbit hole forever.
So its great, a person can test any claim that comes up.
Some weird cult, or non-weird culty group starts pitching something, and you just research and test it to see if it holds water. It can even be fun to try and figure it all out.
Very simply methods can literally destroy the most elaborate new agey and culty structure.
This is why every single new agey cult tries to suppress critical thinking!