We spend days preparing for job interviews — researching companies, perfecting resumes, nailing down our elevator pitches, even picking the perfect outfit. Yet we sometimes fail to devote the same attention to preparing our references. As much as references can seal the deal, if not handled right, they can also do major damage to a job prospect. Here are six strategies to manage your references right:

1. Call ahead – Call or email references in advance to see if they are willing to serve as a reference and if their employer allows it. Make sure to get their accurate contact information and check their availability.

2. Feel them out – It’s important to ask if people feel comfortable serving as a reference. This gives them an “out” if they don’t feel like they can rave about your work performance.

3. Sell them – Tell your reference about the job and why you feel your skills and experience are the right fit. Give them background about the person who may be calling. Start a discussion about the opportunity so you can get a feel for how they might answer any questions about you.

4. Have a B team – It’s customary to have three references, but you should always have back-ups in case one person can’t be reached or the interviewer has other questions.

5. Check your list twice – Before you list someone as a reference, do a sanity check. Are they the most appropriate person? The CEO might look good on paper, but can she speak about your daily work? How are your references’ communication skills? Were they receptive or hesitant when you asked them? Do you feel comfortable with them speaking on your behalf?

6. Don’t resign yet! – Until there is a written offer in your hand and your reference checks have been contacted by your future employer, do not give notice at your current job. There are too many variables that can cause the job to fall through, and you don’t want to be left jobless.

References are a vital part of the interview process and can ultimately make or break a hire. By choosing the right people and arming them with the information they need to give you a great review, you will be better positioned to get that next job offer.