You might want to try just two or three of these suggestions, and if they work for you then try another couple. But it is not easy to be your own critic and coach. Visit the classes of good lecturers to listen and watch. Ask a colleague to visit your class and then to offer his or her suggestions. Ask the Teaching Center to videotape a lecture.
Nothing is quite so revealing.
Or take a small tape recorder to class and simply tape a lecture and then listen to yourself. If the Teaching Center can be helpful, get in touch.