As a final year mechanical engineering student (4th year), I have to disagree with the importance of part time jobs when it comes to a career in engineering.
I have had a part time job in a supermarket for the first 3 years of my degree, including taking up the job to full time hours in the summers of 1st and 2nd year.
I have attended engineering interviews with big companies. 2 interviews for when I was applying for engineering internships (got one of them in the end), and 3 interviews so far for engineering graduate schemes. The interviewer would usually go with you through your CV asking questions about different parts of your CV in order (from top to bottom), and they always skip anything that is not engineering related.
So the nearly 3 years of part time work I have done never got a mention in any of my interviews.
I also fluently speak two other languages aside from English. That's never got a mention neither.
So my point being that, it might be different for other courses/careers, but for engineering, I would advice to focus on the technical kinds of work experience/jobs/societies/hobbies. These are all what engineering employers will be interested in.