Plan your time. A good idea may be to keep a diary. Here you can write all your activities for the day. For example, when you have lectures, when you are planning on doing some of your assignment, what your work hours are, and what spare time you have to socialise. Working things out this way will help you make plans with friends easier, so you don't have to feel left out or stressed because you forgot you had some work to do.
Keep work hours to a minimum. If there is the option to not work, this would be advised. However, it is recognised that many students will need a part time job to be able to afford certain costs such as rent and a food shop. It is therefore suggested that during the term time you keep your work hours as low as you can get them and then over the holidays (Christmas, Easter and Summer), pick up extra hours. When you get a job make sure your employers are aware that you are a student. This will help avoid difficulties if you need time off for an exam and so on. Another option that many students consider is to have a seasonal contract. This is where you only work during the holidays, allowing you to concentrate on your studies.
Have short breaks between work. Whilst working on assignments, have short breaks between working on them. During the breaks, visit some friends and go to town, or what ever you feel like doing to maintain your social life. However, make sure that you do come back to working on your assignment as the longer you leave it, the harder and more stressful it becomes.
Don't be afraid to say no. Often there is a social stigma where if you have work to do and your friends invite you out that you should say yes. However, it is ok to say no once in a while, especially if you are nearing a deadline. If you want to go out with your friends, ask to reschedule so you can join in. Often your friends will agree.
The same idea works for your part time job. If your place of work asks you to stay on longer or pick up extra hours, don't be afraid to say no. Overtime is 100% voluntary in ALL companies. You can not get into trouble for saying no. This being said, if you feel you may need the hours but can't do them on the day you are being requested to, try to negotiate a day that is suitable for the both of you.
The same idea works for your part time job. If your place of work asks you to stay on longer or pick up extra hours, don't be afraid to say no. Overtime is 100% voluntary in ALL companies. You can not get into trouble for saying no. This being said, if you feel you may need the hours but can't do them on the day you are being requested to, try to negotiate a day that is suitable for the both of you.