Hi Carlos,
You ask a very hard question. Keeping students wanting to come to class each time is difficult due to as you say the variety of topics and presentation modes that will be used a various times. I have found that I can keep the students coming by using different presentation and group activity formats. I will end a class with the students working in groups to solve a problem or work on a project and then have the report out the beginning of the next class. I find that they want to come to class so they can share what they did in their group.
As I teach students in need of developing soft skills(job ready skills)I enforce attendance and being on time. As I am preparing them to earn a living in a new career area I want them to be the best professionals that they can be. By being strong on the soft skills I know they be successful since they will have the specific skills needed for success. My students abide by the attendance policy with no complaints or at least to me or in class.
I work very hard to peak the students' interest in the next class by introducing some form of teaser or challenge to them. That way they want to come back to learn the answer to the teaser or challenge.
Also, I work hard on my presentations, to engage the students in the learning process. All these components have to blend together in order to have a successful class.
Gary