A reflection is a powerful tool that will help you become a better teacher. Reflecting on and evaluating your teaching after a lesson is over will give you insights that may save you lots of trouble later. Even a few brief evaluative notes on a lesson plan will help you immensely the next time you teach that lesson.  There are always plenty of other pressing things that need to be done.  Also, you will be surprised at how just a few minutes of reflective writing can help you discover things you would have otherwise not noticed. Self-evaluation is a very important part of every lesson even though it typically takes place after the lesson is over. It requires you to think back on the lesson and consider the answers to general questions (Lesson Plan Self-reflection and Evaluation).