Did you ever have to solve a math problem in school and your teacher told you to give the answer and show your work to explain how you reached your answer? Demonstrating your critical thinking skills in academic writing is similar because you will not only present your claims to your reader but you'll also provide evidence that supports them.
Critical thinking requires people to think objectively about a topic and support claims with evidence; see "What is critical thinking and how can it be demonstrated?" (7:18 section of "Introduction to Academic Writing") for more information. For most types of student writing, that evidence comes from readings published by other authors, such as books, journal articles, and grey literature.
Sometimes students can get stuck in their writing process because they’ve read so much information that they’re overwhelmed with information and can’t figure out how to work all the ideas into an an assignment. Developing an assignment based on what everyone else thinks is extremely difficult because you can’t be an expert on everyone else’s ideas. Instead of letting the readings decide the focus of your assignment, try deciding what points you want to prove, and then identify which readings will help you make those points. Taking that approach means that your thinking is the focus of the work, and you are the expert on what you think.
Please refer to "Understand the Assignment" for a process that helps to identify the key instructions in an assignment description. With that information, you can decide the arguments you want to make in your assignment and the resources you'll use to support those arguments.
To decide what information you want to use from your readings, try a brainstorming exercise that will help you create a strong thesis statement; see "Creating a document plan” (14:34 section of “Introduction to Academic Writing”) for information. Once you have the thesis statement, use a planning tool to map out the arguments in each body paragraph and the evidence from readings you'll use to support them (e.g., "Finalize Your Document Plan" or "Plan Writing with PowerPoint"). For more information on writing academic paragraphs, please refer to the “Writing an Academic Paragraph” video in Paragraphs and the "Body Paragraph Checklist".