At Snap Fitness in Cedar City, I taught an hour-long aerobics class once a week. It's a good idea to make or follow some type of program. I started doing fitness tests (involving counting how many reps of each exercise they could do in one minute) every month so that my regulars could see the progress that they were making. In between the tests, I focused on a different portion of the test every week (for example, push-ups were included in the test, so one week we would focus mostly on doing shoulder exercises), but I did try to make it a full-body workout as well. My class was also more circuit-style, so we would do groups of 3 different exercises for 30 seconds each without any breaks in between the exercises and then repeat that set 3 times before taking a few minutes to get some water and move onto the next set.
Anyway, the day that I was teaching, I would go through my class plan for the day a few times to make sure that I knew what I was doing without looking at the paper in between every exercise. I always got to the gym about 15 minutes early to set up. I hooked up my phone to the speaker for motivational background music and set up a big clock on my laptop (because the only clock in the classroom was behind me when I was standing at the front of the room). If not many people showed up on time, I would wait about 5 minutes before starting the workout with the people who were there on time. I was sure to talk to the owners a little every week, and I got to know the people who came to my class. The time in between sets was good for short conversations, and I was always the last to leave afterwards as well.