My experience comes with having completed college and now being employed at a local university.
If you having an upcoming semester with a tough course load then you are going to have to learn to prioritize your life. First, don't think that your whole life needs to be devoted to doing school work. I think it is very important to also have a social life as well. It helps to give you energy for your studies.
You will need to prioritize your coursework so that you get it completed on time, and so that you do the most important tasks first. If you know you will have several papers or projects due at the end of the semester then do not put them off until the last minute. Go ahead and setup deadlines for small milestones throughout the semester for each major project or paper. That way when it gets down to the wire at the end of the semester you will already have much of the work done.
I say this because the midterm and end of the semester or two of the most stressful times during the semester. You will have exams and projects for almost all your classes, and without proper planning ahead of time you will not be able to get it all done.
Be sure to keep up with assignments, do the homework assigned, read the chapters required each evening so you don't get behind in the reading, and ask your professors for clarification right away on any points you do not understand. By staying on top of things you will save yourself a lot of headache.