No matter what stage you have reached as a teacher, it is always a good idea to get feedback on your teaching.
Much important feedback comes from one's students, of course.
This, the great failing of written student evaluation forms, is often the most frustrating problem that confronts a teacher who is truly committed to improving. Often it is these experts who can help the most. There are two ways to get expert feedback on a class. One is to have a faculty member observe your performance directly. The other is to videotape your class and go over the tape with a faculty member.