How I’d like to do it.
My advice would be to concentrate first and foremost on creating a place where people would want to work, then marketing your organisation to the candidate, they should really want to work for your company, that way you start with a better candidate pool, immediately giving you a better chance of finding the best employees.
Then – even if it feels impersonal, a series of consistent structured tests (IQ and Psychometric) and then formal structured interview questions where the results and responses are noted and then referred onto an independent panel for a decision on hiring. Forget the gut-feel, forget the technical questions, forget hostile interview techniques, they really don’t work. Throughout all this ensure the candidates are treated well and made to feel important.
Sounds like hard work, it sounds like it undermines the hiring manager, it sounds incredibly time-consuming and bureaucratic, perhaps even expensive. But if your goal is to consistently hire good quality candidates it is going to be hard work and you will have to accept that there are some things that cannot be effectively and consistently assessed in an interview situation.
My final thought is that if you have got your hiring right, it is very likely that the most capable, most experienced and most reliable person for a role is the one currently in it. Don’t lose them. Look after good employees they are your company’s most valuable asset. Treat them well and do whatever it takes to keep them.