Bring everything your teacher requires you to take to class. Your teacher should write out these expectations on a syllabus or class description, but if the requirements are unclear, make a point of asking your teacher what you should have with you at the start of each class. Not surprisingly, this almost always includes paper, something to write with and your textbooks. Students should also complete their homework before class begins. If these last points seem painfully obvious, consider that many college instructors routinely deal with adult students who fail to do homework and forget to bring school supplies. Unprepared students are implicitly telling their instructors that class is not a high priority in their lives.
Talk with your instructors. Asking questions and making germane comments tells teachers that you are thinking about what they are saying and making an effort to understand. Moreover, most teachers would agree that students who process information enough to ask questions and make useful comments are enabling themselves to better understand the subject matter. In short, jotting down notes mindlessly is not nearly as useful as applying what you know by asking a question or making a comment.
Come to class on time, every time. This may also fall under the "painfully obvious" category of advice, but many students fail to grasp that class attendance is a requirement for academic success. When a student pays to take a class, she does not make a purchase; rather, she receives an opportunity to learn. Timely and consistent class attendance allows a student to exploit that opportunity, whereas absenteeism represents the student's choice to squander that opportunity. Instead of seeing class as an obligation to be settled with as little effort as possible, students who take an active approach to their learning make class attendance a top priority in their lives.
Work in groups. Studying or working in groups very often requires more-advanced students to understand material well enough to teach other students about it. Additionally, students who need extra help often benefit when the more-advanced student explains ideas in an accessible way. If you are undertaking a group project, look for another serious student (or students) to work with. You can also look for study groups that meet outside of class.
Act like a professional. Understand that class is not just about getting a good grade or job preparation, but also about giving you the opportunity to be a better, more active student. Professionals dress in a way that shows they pay attention to their appearance. Moreover, professionals focus themselves on their task in a way that inspires confidence in the people around them. They do not distract themselves with idle conversation or text messaging when there are more important things to concentrate on.