This tip can also be beneficial to use during class. It often helps to have the assigned reading done before going to class. Doing this will allow you to have some background knowledge about the topic, which will make it easier to follow the lecture and pick out important points. It is logical to assume that during every class meeting, at least one bit of information that is going to be on the test will be covered. Remind yourself of this if you find yourself daydreaming or losing your focus.
People can take in information much faster than people can talk.
This leaves you with extra brainpower just looking for something to do. Instead of letting yourself daydream or focus on other stimuli, put that power to good use by taking extra good notes. This will be beneficial for future studying, and will keep you actively involved with the lecture. Make eye contact with the professor. Get in the mindset that you are having a conversation with the professor instead of just sitting in a lecture.