First off, I've listened to all the "effective meeting" and "effective agenda" podcasts - great stuff!!
I find that one of the biggest challenges I have with wrapping up agenda items on time is clamping off conversation - particularly when there are still good ideas coming in. While it's important to make sure we have all the necessary information, we usually have plenty of other important agenda items to cover as well.
To give you an example, say we're trying to make a decision on the priorities of our team's work for the next 2 weeks. We'll get close to a decision point and the end of the agenda item when somebody suggests another way to think about priorities or brings up another important point that influences the decision. So conversation heats up again and we carry on.
Often, it's critical to make these decisions in a timely fashion, meaning we don't have a lot of time to take the decision offline yet into another meeting & delay the decision.
I suspect this is due in part to several reasons; people not preparing in time for the meeting, people not wanting to give up ownership of decisions to the delegated owner, lack of effective meeting facilitation (we don't have the luxury of having someone in these meetings who doesn't have a direct stake in the outcome to serve as facilitator), etc.
Correcting feedback I'm giving in these situations is along the lines of "when you come to a meeting without reviewing the agenda and being prepared..." or "when you bring a topic to the floor without doing the proper legwork up front to get input from stakeholders...".
I realize it takes time to turn around behavior, and I'm willing to invest that time. But are there other things I can do that will help in the short-term?
I'd love to hear your tips/suggestions for how I can make my meetings more effective.