When you are applying for a job it is tempting to pick the highest level manager you can find as your referee, but it is far more important to choose someone who appreciates your work, and who will give an honestly positive response when your prospective employers call them.
You do not want someone who will say, "Joe who?" when asked about their impression of you.

1. It is a good idea to contact your referees on a regular basis and especially before you send out applications to make sure that their contact details are still current, and that they are willing to talk to people about you.
   This also gives you a chance to update them on your recent activities, which will give them more to talk about, and remind them of who you are, so that they will not sound completely surprised when they are asked about you.
   As a prospective employer it is frustrating to have selected a candidate and then be unable to speak to any of their referees.
   It is really surprising how often people choose referees who hardly know them, and do not inform them that someone might call.
   
2. Your references should be people who know your work and are your fans - that is, they appreciate your work and believe that you are a great worker.
   Prospective employers prefer referees who are in senior positions and who are likely to be able to express possible shortcomings as well as positive characteristics.
   However, if you don´t know any senior managers who are your fans it is better to choose a co-worker who is a fan.
   I recently called one of the referees for a prospective employee and was told, "She is better than average.
   " but I could tell that this was not a high recommendation.
   In another case the referee said, "If you hire this person they will destroy your company.
   " I appreciated the frank response, but I was also amazed that the candidate had chosen such a referee.
   
3. Your referees can make or break your job prospects so collect fans.
   You should always work in such a manner that people will be pleased to recommend you even if your current job is just a stepping-stone to something else.
   Always do your best, and go beyond the line of duty.
   Not only will that get you a great reference, it may even win you opportunities.
   

Employers are usually calling to check references after the selection has been made, so you want to choose referees who will confirm that you can do a great job.
If you have had a bad experience, and you know that your most recent employer was not happy with you, don't list them as a reference.
If you are asked about why you have not listed them, you should have an explanation ready, but hopefully you have some other referees who will be very enthusiastic about you, and it will not be a problem.
It is better to list your most enthusiastic supporters, than your most recent employer.