Check several references. Cross check information, especially negative information, considering its source and relevance. Establish a rapport with the person contacted. Tell the applicant you will be checking references. Record the questions and the responses.
Limit responses to honest, factual statements that respond directly to specific questions asked.
Respond only to job-related questions. Be careful about giving out negative information that is not documented. Verify the identity of the person seeking the reference. That person should have a legitimate need for the information. Keep good records.