One-to-one work with students remains at the core of many higher education career services in the UK, but there is limited empirical evidence detailing the nature of these interactions. Drawing together existing strands of literature on the process and effectiveness of one-to-one career conversations, career decision-making difficulties, and career practice training, we report the findings of interviews with 22 career professionals in HE in the UK who were invited to reflect on their one-to-one practice with university students, describe their approaches and techniques and to identify any challenges they face. Through template analysis, we identified three key aspects to the career professionals' practice: the relationship, the structure of the conversation and specific techniques. The participants described aspects of their practice which diverge from the approaches they were taught during their initial professional training, notably the use of a flexible conversation structure and limited use of career development theories. We identified that the key challenge practitioners reported was feeling that they disappoint some of their clients. We highlight some theoretical implications and offer some recommendations for practitioner training.