Here are top 5 reasons from consistent A students:
Be motivated and show interest – If you hate the course, very likely you are not going to do well. There is a reason why every course is including in your curriculum. You need this course to be successful in your career. Try to learn the topics, you will like/love the course (or at least some aspect of it) and your grades will improve.
Make use of office hours – Don’t shy away asking for help when needed, visit the instructor during office hours. Problems that will take you hours to solve will be solved in minutes if you seek help.
Time Management – Manage your time wisely. Stay focused, don’t multi-task and don’t procrastinate. Avoid last minute studying.
Read the book and Review Regularly – Have a plan to review the course material including the book regularly once a day or once in two days even if it is as little as 15 to 30 mins. This attitude will help you to be successful not only in the course, also in your career.
Take care of your health – It is important to be healthy, especially around exam time. If you are sick, no matter how much you are prepared very likely you are not going to do well.
One more Bonus Tip: Make a study group!