The nature of healthcare means doctors must continually calibrate the quality of their work within constantly changing standards of practice. As trainees move into working as fully qualified professionals, they can struggle to know how well they are practising in the absence of formal oversight. They therefore need to build their evaluative judgement: their capability to interpret cues and messages from the clinical environment, allowing them to judge quality of practice. This paper explores how Australian general practice (GP) trainees develop their evaluative judgement. We interviewed 16 GPs, who had recently completed certification requirements, asking them how they managed complex learning challenges across their training trajectory. A thematic analysis was sensitised by conceptualisations of evaluative judgement and feedback for future practice. Findings are reported via three themes: sources of performance relevant information; sense-making about progress within complex learning challenges; and changing practice as evaluative judgement develops. Trainees actively sought to understand what quality practice looked like within complex and ambiguous circumstances but often found it difficult to calibrate their performance. While reflective practice was key to developing evaluative judgment, feedback conversations could provide significant opportunities for trainees and supervisors to co-construct meaning. A 'feedback community' was available for frequent instances where supervisors were absent or not regarded as entirely credible, although feedback conversations in themselves did not necessarily assist trainees to develop evaluative judgement. There is room for a more active role for supervisors in assisting trainees to consider how to independently make sense of learning cues.