At the beginning of a class, in the first days, an interest survey is a good idea. Have students—anonymously, if they wish—fill out a survey on the topics they would like to discuss. Providing them with some alternatives related to the course content and objectives is a good idea. At the same time, the teacher can get an idea of which language skills students are most interested in working on: speaking or writing, for example. Later, the teacher can compile the results of the survey to use as a plan for the curriculum.
Taking into consideration student interest and goals increases student motivation and retention.