If you’re still in college, most employers are only able to look at what college you attended. There are tens of thousands of students who have this bare-bones approach. If you’re able to get references from prior teachers, you can really stand out above other applicants.
Building relationships with faculty members or college advisors associated with your degree is ideal for a recommendation. As for past or current employers, it doesn't matter if you worked at a local Baskin Robbins and are applying for a job in engineering - employers value any prior work experience alongside a full class load. Any relevant references are optimal when entering the workforce as they can speak to your abilities, work ethic, and motivation.
Family and friends are great to have but putting them down as references is not professional. Remember that recruiters may check your social media, so don't try to fool them by claiming your friend is a former manager. If you're hesitating to put a reference on your application who will have anything to say that's less than positive, then leave them off. This should be an obvious point, however far too often, applicants will simply throw on a previous manager or teacher without asking if they can list them as a reference. If there is hesitation from the person you're asking, do not list them - a sign of hesitation is often negative.
The most important aspect of picking references, is notifying them beforehand. From their perspective, there would be nothing worse than receiving a random call from a stranger, asking them about a prior employee or student. When contacting your reference, a phone call is preferred, but an email will do.
After the interview process is over, regardless of whether or not you get the job - be sure to thank your references. Even a simple email will go a long way. If you want to take an extra step, a handwritten note, or small gift card are great. Odds are, these people will be used down the road, and it's a good idea to have them in your networking group.
If you're in dire straits about adding anyone to your reference pool in the near future:
University-sponsored networking events: It's a fantastic way to meet people who are hiring, and share your common college background.
Volunteering: This looks fantastic on your résumé if you lack prior work experience, and it shows that you are going above and beyond to get involved and contribute outside of class.
Informational Interviews: While companies you're interested in may not be hiring, asking someone who works there to coffee or lunch is helpful the next time a job opens up - this shows initiative and you will be top of mind.