Upon receiving a professor's syllabus, the first thing that I check is How much is Class Participation worth? The obligatory grade is typically around 20%! Meaning, if you don't speak up and get your voice in the discussion, you could lose out on a fifth of your grade.
I think it goes without saying, but I'll mention it anyway: come prepared and read over all of your materials for class. Your professor knows if you haven't read something, and you don't want to be called out on it or be docked participation points for not preparing. I like to take some quick notes about possible talking points for class, that way I have my main talking points ready to go if called upon. I also have my laptop open so I can easily search the downloaded readings or case studies for key words mentioned in the discussion if it reminds me of an important point I want to mention.
You can also earn points by opening a case discussion. This is one of the easiest ways to get participation points. Again, I typically prepare some bulleted notes about the case that I can then reference back to when I open a case. These notes also help me recall other various facts from the case that I want to bring up in the discussion as well.
Most professors I've had give you plenty of opportunities to speak up in class and get those participation points. Another common way to earn participation points is to bring in an interesting article and discuss how it relates to that week's class readings.
In all, it's important to participate in the conversation. You may have an interesting perspective on the topic, and if you don't raise your hand, your classmates may never learn that thought-provoking fact from you. So, raise your hand, and speak up!