New recruits not joining or backing off at the last moment - tips and tricks that you use to make sure the candidates you have made an offer to do join?

Hi All, I wanted to know how you manage hiring in the IT industry especially the part where new recruits fail to report to work or intimate at the last minute that they have changed their mind about joining. Even after keeping in touch with the candidates up until their joining date, they fail to inform me they are having a change of mind.
Can you all share some tips and tricks that you use to make sure the candidates you have made an offer to do join? I understand there will be a few dropouts but I would like to hear from others in a similar situation as I am in.
Thank you.