The ability to think critically is not easy to learn. For whatever reasons, humans have some difficulty in doing so, that's why religions get away with teaching what they do, and populist politicians too).
Here's part of what a local uni says on the topic:
Critical thinking and writing involves:
Words that are associated with critical thinking include: analysis, evaluation, comparison, making judgements, drawing inferences, problem solving, developing an argument. Link: https://www.uws.edu.au/hall/hall/critical_thinking
- being able to question and evaluate information
- solving problems
- thinking beyond the immediate situation
- looking at the big picture and the context of a topic
- asking questions about different aspects of the topic – What? How? When? Who? Why? What if?
- looking at theory and asking how it relates to practice
- reading different viewpoints about issues and forming your own conclusions
- reflecting on your work and deciding how to improve it in the future.
Also, it should not become a club to smash down someone else's argument. Many courses on CT will emphasise the need to take a charitable view of other's arguments. And that can be difficult to do in heated argument. I think that's particularly needed where we deal with people that may have little understanding of how to think critically. What's the point of insisting on CT rules, when the other arguer has no understanding of CT.
I was about 17 when I got involved with the JWs.
I was only a below average student then, and it was in the TMS that I first learnt to be questioning in my research. Just the simple step of asking, how, when, where, whom and why, was a great step forward. The TMS textbooks in the early 1950s, like "Qualified to be Ministers," helped many of us in that generation of witnesses to take the first steps in learning to be critical thinkers and not just gramophone records in speaking assignments. Of course, when eventually events like 1975 came along, the critical thinking seeds planted muc'h earlier, bore fruit and we found we'd been led down a dead-end alley, not just about the JWs, but about religion in general. Humans in general are not naturally clear thinkers, so I'm glad of the of assistance they gave me in learning to think a little bit for myself, to give 60 minute (in those days) Public Talks, to work a room and so on.