Immersion journals are key tools for conducting contemporary netnographies. This How-to Guide explains the need for an immersion journal in netnography and how an immersion journal and its immersion notes set netnography apart from other approaches to ethnography online. It then provides an updated set of guidelines to create and contribute to an immersion journal. It outlines the key characteristics of an immersion journal and relates them to the rigour of contemporary netnography. The guide discusses useful formats for the immersion journal, as well as its length, frequency of use, and utilisation in teams during the research project. The final section provides ethical protocols for the use of immersion journals in netnography.