Focus on the agenda. The key to great meetings is great preparation, and the key to great preparation is the agenda. List who, what, where, when, and why, and be sure it's in everyone's hands days before the actual meeting. Whenever possible, include attachments that convey the most important points of information, so people can study things beforehand. And keep it simple.
Most meetings fail because they try to do too much.
A few key items are all that most minds can handle during a typical meeting. Never publicly scold anyone for coming in late, but do talk to the person afterward. And if someone consistently can't make it on time, then either hold the meeting in his office or suggest that maybe his attendance isn't necessary. Ministry is cyclical. Which means that you can mine last June's agenda for this year's ideas.