The contribution explores the use of peer observation and formative feedback as key strategies for teachers' professional improvement. Through the practice of mutual observation, teachers can develop didactic and interpersonal skills, encouraging reflective and collaborative learning. It analyzes how these practices can be effectively integrated both in initial and in-service training, with particular attention to the role of feedback, which is crucial in supporting a process of constant and constructive professional growth. The article also provides practical recommendations for implementing these tools in the school context, promoting a culture of peer collaboration that values continuous training and best practices.