Recognize that in order to succeed you need to make decisions about your priorities, your time, and your resources.
Don't let friends and acquaintances dictate what you consider important
Morning, afternoon or evening? Find spaces where you can be the most focused and productive. Prioritize these for your most difficult study challenges.
When you contribute your best to a class, you, your fellow students, and even your teacher will benefit. Your grade can then be one additional check on your performance
When you have an issue with an instructor (a questionable grade, an assignment deadline, etc.) put yourself in the instructor's place. Now ask yourself how you can best make your argument given his/her situation
For example, if you don't understand the course material, don't just re-read it. Try something else! Consult with the professor, a tutor, an academic advisor, a classmate, a study group, or your school's study skills centre.