Part-time teachers form a growing proportion of the global Higher Education (HE) workforce. Their backgrounds can vary from Graduate Teaching Assistants (GTAs) teaching for the first time, to practitioners bringing workplace experience into HE and sessional teachers, all with differing professional development needs. This paper builds on previous research to consider structures and practices promoting sustainable, effective professional development for part-timers, to propose proactive holistic professional development, and raise institutional awareness of the challenges of reaching part-timers. A case study exploring the lived experiences of part-time staff illustrates key features of part-timers' preparation for their current work and future aspirations.