Hehehe that's what graduate school teaches you! You can learn most all the proper and improper methods from books, but it will be the practical that helps you and your profs realize whether you CAN do clinic.

What books have you read? Why are you asking mentally unwell patients on a mental health support site, how to think critically? What information do you expect to receive? What questions have you asked others? What other course work have you done to learn critical thinking? Do you KNOW how to think this way in reference to other objectives? How much thinking about how things work together, how things affect each other in the world, have you done already? How old are you? Do you think you have had enough life experience to gather enough knowledge to guide others? Have you googled this for more resources? Can you figure out how all these questions go together?

Critical thinking means correct thinking in the pursuit of relevant and reliable knowledge about the world. Another way to describe it is reasonable, reflective, responsible, and skillful thinking that is focused on deciding what to believe or do.

A person who thinks critically can ask appropriate questions, gather relevant information, efficiently and creatively sort through this information, reason logically from this information, and come to reliable and trustworthy conclusions about the world that enable one to live and act successfully in it

Good wishes!