Be there at least a half hour before the meeting to make sure that everything is set up the way it should be, and that all equipment is plugged in, turned on and functioning properly. DO NOT Disturb. Make sure that you and only you have control of the lighting during the meeting. Tell them what to expect . Tell the meeting attendees specifically what they will learn in the course of the meeting and how they will be able to apply their new knowledge.
Clear goals keep attendees focused on their own responsibilities as active participants.
If your meeting is small but your room is large, either remove extra chairs to keep the audience closer to the speaker, or ask everyone to move up to the front rows. Survey every participant to make sure that you addressed your topic comprehensively and understandably. Ask everyone to look at the survey form at the start of the meeting so they will know what to look for. Draw up an action plan to resolve any issues revealed in the surveys. Look for ways to do all four.