1. Do your homework.
There are many benefits to completing your homework on time. First, you'll have an opportunity to put into practice what you learned. Second, you'll get an idea of what concepts you don't fully understand, and you can seek additional help. Third, you'll be on the same page as your professor and won't fall behind. Lastly, you'll earn the points you need to maintain good grades.
2. Always attend class.
Most college classes meet once or twice a week, which means that missing one class can drastically affect you. It will be up to you to make sure you're regularly attending class and only taking off when it's absolutely necessary. Missing class could not mean not learning essential material or not taking an in-class quiz, and there's a good chance you'll fall behind. A class-participation grade is given in some classes as well, so skipping a lecture could mean losing points.
3. Meet all class components.
Make sure you attend all required meetings even if they are outside of class, such as field trips scheduled by your professors or group study sessions. It's your responsibility to contact your professor and explain if you're unable to attend a scheduled class component. It doesn't hurt to find out if you can make up for missing an event, either by attending on another date or by completing an extra assignment.
4. Focus on what interests you.
Most undergraduates are expected to take a few courses outside their area of study. However, you can mix your class schedule by taking a couple of general education courses and a couple of courses within your field of interest. It's also wise to take electives aligned with your major. Ultimately, you have a greater probability of earning good grades in classes that interest you.
5. Be disciplined and organized.
You can get organized by jotting down important due dates in a physical or digital calendar. Make sure not to procrastinate - allow ample time for studying and completing assignments, rather than cramming the night before their due. You'll need to show up to class on time, complete all assigned readings before class, and take good notes during your professors' lectures. These positive study habits can help you earn the good grades you desire.
Understanding the grade breakdown presented in your course syllabus will also help you stay on top.