Hi,
I can tell you how I do it with my company. We have prepared a reference report that is objective type. During the joining formalities, I hand over the reference report to them and ask them to get it filled by their respective reference person, whom they have mentioned. After that, we call up the person who has provided the reference to thank them for their time in filling it out and clarify things if required. For instance, if they have mentioned excellent performance, we ask them for specific instances, and the same goes for negative feedback.
Regards,
Mahalakshmi
HR