Classes come first. This may seem obvious, but some people forget why they're in college in the first place. You are there to get an education. With this in mind, do not schedule work shifts or social events during your class time.
Schedule work predictably. Try to get the same shifts throughout the semester. Mondays may be different then Tuesdays, but as long as every Monday is the same, it will be easier to remember. Try to make it so that you can get work and class done at the same time everyday. This will set a better routine for you.
Schedule your study times. This will prevent you from making plans and forgetting your homework.
Leave Fridays open. You may have class or have to work a shift; that's fine. Just leave the studying for the next day. Take Fridays for some time for you to go out with your friends or just relax.
Study Weekend Mornings - If you want to have quiet study time in your dorm, try weekend mornings. This is when everyone sleeps in and the lounges are empty. Take advantage of that.
If you have a free hour between one class and another, take your textbook and get some reading done. The more reading you get done, the more time is left for you to have fun with your friends.
Don't eat alone. It may be tempting to take your lunch up to your dorm and eat by yourself while catching up on homework, but don't do that. Eat in the dining hall and meet up with your friends. This hour spent with your friends can be just what you need to get yourself back on track.
Don't allow distractions. If you are studying, try to focus on that. Interruptions can hinder your thought process.
Take breaks. Studying can make a person restless. If you start to feel this way, get up and walk around. Take a half hour to talk to your roommate or your neighbors. Just remember to keep an eye on the clock.
Keep track of scheduled events. If you hear about something that you want to go to, write it down in your planner. It is easier to schedule around those events if you know when they are coming.