We waste a lot of time in meetings—so much that half of all business meetings are considered a waste of time. The most common complaints of meetings as time sucks: they don’t yield definitive results, the attendees are poorly prepared, and the process is disorganized. And in this go-go-go work age when all time is precious, people turn to missing meetings, doing other work during meetings, and even daydreaming during meetings. All told, these unnecessary meetings cost U.S. businesses $37 billion each year. And they’re happening in your office right now.

But take heart—whether you’re organizing or attending these meetings, greater productivity lies in four simple meeting-etiquette tips:

• Show up on time. You wouldn’t outright say your time is more important than your coworkers’, but you sure show it when you come late to meetings. Imagine how your coworkers feel to wait for you or to have to catch you up after your late arrival. If you are habitually late, this can be a sign of a deeper issue, such as an overbooked schedule or troubled time management. And it should go without saying that if you are required to be at a meeting, or if you respond that you will come, that you actually do attend. People are counting on you to be there, and your sudden absence can throw off the meeting as well as your reputation.
• Have you ever walked into an interview where the interviewer was hurriedly reviewing your resume for the first time? That probably made you feel 1) not so important and 2) like that person didn’t have their act together. So don’t be that person at a meeting. Come prepared with the meeting agenda and any handouts emailed in advance, and with notes on your thoughts and speaking points. Thoroughly review any background materials. If you have a critical role in the meeting, check in with the organizer to see what’s expected of you, and be prepared to answer any questions that fall in your wheelhouse.
• You might find yourself representing your company at a meeting of your peers from other organizations. And you might not know anyone. Whether there’s one stranger in the room or one hundred, be social: introduce yourself, smile, shake hands, and exchange business cards. Familiarize yourself with the key participants and any people in your role at other organizations. This will help you be more tuned in and productive at future meetings.
• Participate without hijacking. The first rule of participation? Be present! Not just with your tush in the chair, but by actually listening, taking notes, and responding as appropriate, versus doing other work or playing on your phone. (This is true even when you think the meeting should have been an email. In person, eyes are judging your behavior, not your intentions.) So now that you’re present, the second rule is to participate! Your meeting invitation means you have something worthwhile to contribute. Offer up information and insight without feeling like you have to comment on every little thing; that can turn into hijacking the meeting from the organizer. And while you’re busy not hijacking, make sure you stick to the agenda instead of delving into something off topic or relevant only to you. Always let the organizer steer the show, even if it means steering you back on track.