This article identifies the latest researched practices for preventing school disengagement resulting in Early School Leaving (ESL) within the European Union, and which are significant as we transition to a post-COVID-19 school environment. Drawing from an extensive review of European and U.S.-based research literature on the prevention of ESL and student disengagement and a secondary study examining teachers' practices, this article identifies the practices that are implementable at the classroom level to promote students' engagement, foster school-family relationships, and which can be readily adapted by teachers and parents as schools reopen. The findings show that while some practices which ameliorate ESL are already known, others such as 1) early-on identification of students' disengagement; 2) strong peer and teacher relationships 3) high teacher expectations; 4) classroom level behavioural practices targeted to student engagement; 5) nurturing, safe school environments; 6) challenging curriculum; and 7) partnerships between schools and parents whereby both are trained to view schools as a joint learning enterprise are critical. We conclude by stressing the pro-activity of schools, teachers, and parents in using these practices, so that teacher-student relationships fostered by trained and dedicated teachers can keep students engaged and in school.