Technology-enhanced collaborative writing (TECW) for second language development is receiving increasing research attention from educators and teachers. However, there have been few review studies investigating how teachers implement this activity, how they use technology for the implementation, and what challenges they have. To better prepare practitioners to use digital tools for collaborative writing among their students, we reviewed 42 relevant studies focusing on their implementation identifying nine main TECW practices. These include: receiving teacher training; grouping students; training students on collaboration; training students on technology; providing students with new knowledge of writing; monitoring processes and giving immediate help; providing sufficient autonomy to students; evaluating outcomes and giving feedback; and encouraging students' reflection. Technology could support TECW implementation by expediting information delivery, developing group workspaces and group chatrooms, recording students' writing and collaboration behaviours and visualising their thoughts, enabling teacher commentary and information post, and presenting organised, analysed records of the TECW process. Challenges to TECW included: students' reluctance to collaborate and difficulties using new technology. Based on the review, we argue that teachers can influence the implementation of TECW from cognitive, metacognitive, behavioural, and motivational aspects. Teacher training, student autonomy, and the size of writing groups are potential areas for future research in TECW.