Second interview:
Always bring your top two or three candidates back for a second interview. Second time round they will be more confident because they know they are on the short list and it can bring out different behaviours – sometimes for the better and sometimes for the worse – either way you learn something about them. Also, if possible, get a colleague to interview them as well on the second visit. It gives a second opinion.
A test: It is a good idea at the second interview to ask the candidate to do something relevant to the job. A sales person might give a presentation on their previous company’s products. You could ask a programmer to do a test etc. etc.
Phone references: Then once you have made your selection get phone references and call and speak with as many of them as possible. Remember to check a few details of their CV with the referee just to check the truth of it.
If you do all of this then it will increase your chances of getting the right person for your job. Top it all up with a three month probation for the new employee and make it clear that they have to pass that to stay with the company.