Step One:
Watch this short video.
Step Two:
Write a formal email to your teacher.
If this is near the beginning of a course, tell your teacher a goal you have for the course or what you are looking forward to. Remember to use your best, formal language, check for spelling and grammar, use a greeting, and an appropriate sign-off.
Check the subject line is short but appropriate.
If this is later in the course (such as in the middle or near the end), email your teacher stating how you met a previous goal, something you're proud of that you have accomplished in the course, or an email of appreciation.