Observations aren't as scarey as they sound. After 40 years of teaching, I still get butterflies before EVERY class because I want it to be absolutely the best possible experience for everyone. When I'm being observed, I've been known to throw up. Sooo. given that, please try to consider the observation experience as simply a collegial conversation.
One example that illustrates how somone coming into a classroom can be mistaken is one where a little boy was being given special treatment. One of my comments was, "Why is John able to stand while the others sit? Why is John allowed to move around the classroom"? The answer was that John was legally blind. An observant observer may have caught that but I didn't. So much that happens in a classroom is so unique that anything that is discussed with you as a student is negotiable. Hopefully, your communication skills are such that we can explore ideas together.
Generally, I make a list of Commendations and a list of Recommendations. When I return the next visit, hopefully, the student teacher has addressed at least one of the recommendations. What I look for most is: "Are you improving?" And I really am on your side. Your success is my success so please relax, enjoy the process, be open. During the pre and post observation conversation, a lot of information can be exchanged.
Sometimes the pre-observation is done by email. Unless you are on contract or it is completely unavoidable, the post observation should be done face-to-face; however, the actual filling out of the coaching cyle form is the responsibility of the student teacher.