1. Look at your whole semester. When are the major due dates and exams for each class? What other major plans do you have? Are there any times when you know you won't be working? When will you be traveling? Seeing family or friends? Mark major deadlines on your calendar or an everything notebook. Block out times when you have outside plans. Knowing what your major deadlines are, and getting ahead of them, will allow you to put work away and fully enjoy those times when you want to spend time with friends or family.
2. Figure out exactly what you HAVE TO get done by the end of the semester. Maybe you have a semester long project or you need to finish a resume or apply for law school.
3. Make a plan to get THOSE THINGS done. You will be very unhappy if you get bogged down in day to day assignments and let major things go untouched until the last minute. Break major projects and goals down in to pieces. What order do you need to do those pieces in? Make a deadline for each piece and put those deadlines on your calendar, paying attention to other deadlines that you have to meet. You can do this in a calendar, or on a spread sheet, or both.
4. Set rewards for yourself when you get important projects done or meet major deadlines. This might be something as small as a bowl of ice cream, but it helps to have something to look forward to.
5. Every single Sunday, look at those deadlines. What do you need to get done this week? How will you get it done? I organize my entire work week in advance (at least loosely).
As you begin the semester, it's important to keep your eyes on the prize and remember what your ultimate goals are for being where you are. Work advice aside, you also need to take care of yourself. Time without boundaries leads to less productive work in the long run. Don't be a "work martyr" at school or at work. Sleep deprivation affects your productivity and health. Anything less than 7 hours of sleep will affect your ability to concentrate and learn. Work when you work, and rest when you rest. Don't allow work and work stress to rule every waking moment. The way to avoid that is to be completely focused during work time, and put work completely away during rest / play time. More on how to do that soon.