Well intended people can often do the most damage. This is often the case when it comes to the people who have agreed to be your references. Good references need to be carefully selected and well coached.
When it comes to selecting your references, here are a few guidelines.
1. Choose people who have seen you work. People in your personal life may have no idea about how you are at work. And adding people with big titles who have not worked with you directly may not be the best reference.
2. Choose a cross representational group which includes a boss, a peer, a direct report or maybe a customer. It is a red flag to a prospective employer if a boss is not included on the list.
3. Choose people who are articulate and accessible. Job offers can get delayed if a prospective employer cannot reach your reference. Also if you are uncertain about how your reference will represent you, think twice about adding that person to your list.
In terms of coaching your references. Make sure your references know exactly what your current job search objective is, especially if it is different than the role they have seen you in. Also be sure that they have a copy of your current resume and a copy of the job posting. You want to make sure that if and when that reference is contacted, they can clearly and confidently convey to that prospective employer how you are the best fit for the job.
Therefore good selection and coaching of references will minimize the chance they will sabbotage your job search.