Despite the importance of writing and numerous approaches to the teaching of this skill, tackling EFL writing is still one of the challenging areas for teachers and students. In fact, an educated person in the process of writing needs not only a certain amount of L2 background knowledge but also metacognition to be a successful writer. There have been lots of researchers who showed how to incorporate basic thinking strategies into writing. Therefore, this book compares practicing critical thinking skills and self-assessment, which are both kinds of higher order thinking in the process of writing, to find out which one is more effective on writing achievement of EFL learners. Findings could be well-applied to writing classes and they are likely to be of great interest to teachers, syllabus designers, and researchers.