How to recruit a PhD student without a strong connection to teaching?
PhD studentships are quite often advertised like "normal" jobs, i.e. on general job boards/recruting websites. If you have contacts, by all means use them. As for evaluating the candidates, similar guidelines as for evaluating applicants for any jobs apply. I don't think there's a one-fits-all answer. Note that the hiring process may also depend on what institution you'd be working for. They might have an HR department that screens/selects the candidates.