As a seasoned instructor I practice eye contact and floating around the room. It keeps the class engaged and I have found eye contact alone gives the student the 'OK' if they have a question.
Repeat, repeat, repeat. I incorporate as much information as possible that the students needs to retain for their carrier and/or the national exam they will be required to take. Repeating often is key for memory. Also, not only verbally repeating but giving handouts or lab exercises to reinforce key points and lecture.
All these skills and techniques took years to develop. This lesson is great… >>>