Why do you need to self-reflect?
Well, in asking that question, you’ve begun the process of self-reflecting! Congrats.
You need to include self-reflection as a professional development process because 1) like your mother always said of eating the stuffed, green peppers, its good for you, and 2) its becoming a job requirement. Along with many other state across the nation, the Minnesota Department of Education provides districts with a template to address the recent teacher evaluation requirements. The mandate requires teachers to participate “in on-going professional development activities and [collaborate] with colleagues and families to advance learning for teachers and students.” 
Four domains are presented in the program with Professionalism being the one on which I will focus for this post. The State of MN presents the following outline for the Professionalism domain:
DOMAIN 4: PROFESSIONALISM Indicator A: Reflects on teaching practice
i. Uses self-reflection to improve instruction
ii. Uses feedback to improve instruction
iii. Plans for professional growth
In this post, I will address the first sub-domain of self-reflection, why it should be done, what it is, and how it can be done.
Why should I self-reflect?
As we reflect on the reasons we do what we do, we get a sense of ourselves in the process. When you have abetter sense of your personal motivations you better set yourself with the best environment to help you succeed. Associate professor of education, Lynn Zimmerman, described the results of self-reflection as a “transformation” that influences how we perceive our self. 
Professionals who regularly reflect experience an increased sense of confidence, control, and passion.  The way our colleagues see us also changes as reflective practices allow us to more readily and accurately articulate our professional vision and mission. Our teammates will perceive us as driven, focused, and competent.
So what does it mean to “self-reflect”?
On the self-reflection rubric, an exemplary teacher is described by the state of MN as a teacher who “continuously and accurately assesses his or her own effectiveness using lesson artifacts and student data to identify areas of strength and areas for growth.” 
As I mentioned in my post How to Motivate the Un-Motivatable, understanding the “why” behind the “what” is of utmost importance to promoting growth in others, and in the case professional reflection, yourself.
Reflection should allow a teacher to easily explain the reasons they do what they do beyond the typical “I do it for the children schtick.”.
Crystal Holyn Holdefer defined self-reflection like this: “Self-reflection in its simplest form is asking yourself thought-provoking questions so that you can develop a deeper level of understanding about yourself.” 
Use these questions from Vivian Beck to guide your reflective activities, to figure out the “why” behind “what” you do each day. 
10 Professional Reflections Questions
1. Where do you see yourself in five years from now?
2. How will continue making an impact in our changing world?
3. Do you have a desire to become an instructional leader outside of the classroom?
4. Are you drawn to curriculum development?
5. What areas of specific areas of instruction are your strength?
6. Are there areas of teacher performance that could use some attention?
7. How strong are the relationships you build with your students?
8. Do you involve parents in student learning?
9. What is your ultimate goal for each student?
10. If you could change one thing in the way you do “business” now, what would it be?
As teacher evaluation mandates are adopted, an understanding of the how and why of self-reflection will be necessary for teachers to meet with new demands of professional development. Self-reflection helps teacher understand the reasons for their actions. reflection increases an individual’s sense of confidence and passion. Self-reflection allows those who practice it, to speak of their professional goals with clarity and precision. The use of guiding questions will facilitate the self-reflection process and help teachers to realize its benefits.
Now, if you’ll excuse me, I’ve got to go examine my motivations for writing this post.