Set aside time at the end of each school day for writing in your journal. Make journal-writing a part of your daily routine to ensure that it gets done. Find a quiet place, such as an empty classroom, the school library or your home office. Give yourself at least 10 minutes but don't stop before you are done recording all of your reflections.
Target different aspects of your teaching to reflect upon. Ask yourself if the objectives of your lessons were clear, if the students stayed on task, if the time management of your lessons worked and if students seemed to benefit from classroom exercises. Take special note of lessons that worked particularly well and those that didn't work out as planned.
Record your growth over time throughout the year. Take note of small successes and improvements in your lessons and in the classroom dynamic. If a student looks unhappy or excluded at the beginning of the year, track the progress of his integration into the normal classroom dynamic. Identify other problems early on and keep track of any improvements.
Reread your journal occasionally throughout the year, especially when the year is over. Look back on your successes and failures. Use your journal to make improvements to your curriculum and lesson plans for future classes.