How do you choose who to put down as a reference? It’s an important choice you’ll have to make when you’re putting together your job application. One wrong word from a less-than-enthusiastic reference can quickly knock you off an employer’s list of candidates.

On the other hand, a strong endorsement from the right reference can convince an employer that you have the right skills and experience to excel in the job.

References are such a powerful tool because you can promote yourself all you want in a cover letter, resume or portfolio, but you have less autonomy over your references. Whereas you can’t control what your references say about you, you can control who you select as a reference. And, it’s a crucial choice to make, with serious consequences to your job search.

Here are thirteen tips for choosing the best references to use in a job application.

13 Tips for Selecting the Best References

1. Ask your manager or a past boss, but be careful. In an ideal world, a direct manager or supervisor would act as your reference, and would be willing to discuss specific examples as to how you excelled in your role, and added to value to the team, department or company while in your position. The absence of a supervisor in your group of references can incite questions about your performance on the job.

Employers will understand if you leave off a current supervisor because you don’t want to jeopardize the job you have already.

In that case, you might say a reference from a current supervisor can be provided if an offer is pending. It is then more important to include a past boss.