Giving the students a role (like a reporter, detective or researcher) can help them by providing a context for creating and asking questions, especially when coupled with a scenario that they have to "solve". For example, presenting them with a "crime scene" and "suspects" (role played by the instructor and having different personalities and characteristics to keep it interesting) and then asking them to create the questions they need to ask to solve the crime is a very useful critical thinking that students find both interesting and engaging. This method is also helpful if you are a frustrated actor and want to practice your technique.