The biggest mistake that is made during the reference checking phase for key hires is that it is considered a formality, a tick box exercise, given to a junior to perform, sent out on email or even worse its outsourced to a third party.
Reference checking questions if asked in the right way can provide real insight into a candidate from the people who have potentially been in the shoes your about to fill.
1. Were you asked to be a reference by (candidate name)?
2. What did (candidate name) learn during their time with your company?
3. If you could give (candidate name) a single career suggestion, what would it be?
4. What circumstances frustrate (candidate name) the most?
5. How well does the (candidate name) manage pressure, stress, or crisis? Can you provide an example?
6. How did the candidate respond to your management style?
7. Would you rehire the candidate in the same role or something different?
8. Have you recommended the candidate to other people within your network?
Final advice would be to not just rely on the references supplied by the candidate. Use your social, professional and industry networks to see whom you know in common with the candidate, and reach out to them for their insights.