This chapter discusses best practices for conducting a conversation-analytic (CA) investigation into (discourse) particles (or discourse markers). Particles are ubiquitous in talk-in-interaction, making them an attractive research target. CA research into particles aims to elucidate their interactional deployment in the language under study and, more generally, to develop a deeper understanding of the infrastructure of social interaction. The chapter discusses conceptual underpinnings of the CA approach to analyzing particles: first, its orientation to social action; second, its emphasis on positionality (including the particle’s position in a turn, a sequence, a repair segment, and a conversation as a unit); and, third, its use of particular evidentiary procedures (such as the ‘next-turn proof procedure,’ positional deployment, distributional evidence, and deviant cases). The application of these principles is illustrated with two case studies: a semasiological study of the Russian particle nu and an onomasiological study of how courses of action are launched via so and oh prefaced turns. The chapter shows that, while fraught with challenges, a study of particles can lead to important and unexpected findings about social interaction.