You can tell a meeting will be effective right from the start because of the way it is opened. Is there a clear agenda? Are participants introduced? Are goals explained? Following are some key things to consider when opening your meeting.
Is everyone present or do you need to wait a few minutes, or even modify the order of items in the agenda because key participants haven't arrived yet? For meetings in person, this is easily done by looking at who is present, but for those involving remote employees and contractors that are dialing into a conference line or web meeting, you should do a quick roll call to see who is present. Note that if you always start meetings on time, people will learn how important it is to show up promptly.