Use a variety of people
Whatever you do, don’t use three people from the same company and leave it at that. You want to use three to five people with whom you have worked closely but who came from different places. If possible, use an educational, a professional and a personal reference. In addition to those, a reference from either an internship or voluntary work is also desirable but not necessarily essential.
For personal references, avoid listing family members or anyone you are in a relationship with as companies cannot accept these and will instead ask you to provide a friend’s details. If you have had your own company, former customers and business acquaintances are acceptable for this.
Get permission to use someone as a reference
Don’t just list someone as a reference - be sure to ask them first. Not only is this common courtesy, it also makes the process easier for the company. Companies often find themselves waiting on referees to respond, delaying the application process and sometimes costing the applicant a job due to time delays. And don’t delay asking them because you’re afraid, most people will be flattered and if they aren’t, ask someone else.