This article aims at helping teachers make effective use of language portfolios in an EFL/ESL context. This is through proposing and making clear the steps of integrating them into their teaching and the way learners' training into their use needs to be conducted to promote their reflective and autonomous learning. These range from identifying the students' readiness to autonomous learning to teachers' assessment of students' portfolios and their evaluation of this process. It is worth noting here that, this training process is being carried out on a sample of undergraduate students at the department of English of Abdelhamid Ibn Badis University of Mostaganem, Algeria.