Always Be Prepared
Okay, so I stole this from the Boy Scouts of America, but the principle still stands. In my experience, you can be prepared without having a successful meeting, but it's next to impossible to have a successful meeting without being prepared. To be prepared for a meeting, you need to do the following:
Have an agenda. Go over your notes from your last few business meetings and start the next one with a quick recap. Go through any deliverables from the previous meeting and get updates on their progress. Then, get into the meat of your meeting. Before the meeting disbands, ensure everyone is aware of what is expected of them before you meet again.
Bring any handouts/presentation material needed. If you're discussing the budget, make sure everyone has what they need. If you're presenting a PowerPoint presentation, make sure the computer and/or projector is working correctly. The only thing worse than a boring meeting is a useless one.
Without these preparations being made, you run the risk of otherwise productive meetings being a waste of your colleagues' time. Of course, this can be annoying (but forgiven) once. Beyond that, you begin to gain a reputation. With that reputation gained, you can prepare until the cows come home and you'll still be fighting an uphill battle for respect and attention.
Fail to prepare and you're preparing to fail. I didn't make that one up either, but neither did the Boy Scouts, so we're covered.
Mind Your Manners
As I said, so much of running successful companies, productive meetings, t-ball practices, anything, depends on common human decency. We create Robert's Rules of Order and the like, in part, because we can't always depend on that common decency being… well… common. At the end of the day, though, simply showing people the respect they deserve can mean the difference between taking part in (or leading) an effective meeting or an hour-long argument. Here are a few tips:
Show up on time. It seems simple enough, but show people you respect them by first respecting their time. Keeping the rest of your meeting waiting ensures only that they quickly forget (or stop caring about) why they were there in the first place.
Listen. This is especially true for people who regularly lead business meetings. Stop talking and listen. Unless you have simply called everyone in for information dissemination (which should be few and far between) you should open up the floor more often than you speak to it. The people you work with were hired for a reason; let them speak. Not only will you likely learn something you wouldn't have otherwise, you will show your co-workers that you respect their knowledge. An acknowledgment of others' usefulness can go a long way in the office.
I once had a defining moment as a professional in which I laid it all out on the line with my boss. I had worked all night putting together a presentation, and when I began presenting it, I could see he was busy working on something else entirely. New to the profession, I said nothing for a while, but eventually my patience ran thin and I began packing my presentation, apologizing for having apparently wasted his time, and I would reschedule for a time when he wasn't too busy for me. Luckily, my boss was a good (if over-encumbered) man and he quickly apologized and I continued the presentation. The fact is, people have set aside time for your meeting. They have set aside time in their busy days for you. Show them respect by avoiding multi-tasking.