Meeting etiquette can be broken down into the 5 Ps.
Preparation:
Get your act together before the meeting begins. Bring your notepad and pen, or laptop to take notes. If you have additional information regarding the topic being discussed, take it with you. You may be called upon to contribute to the discussion. If you have reports, articles, or any documentation, you may want to have a copy for each attendee or at least for the meeting host.
Punctuality
Be on time. Be no more than 5 minutes early. It will give you a chance to settle in and do any preparations. You may even have a chance to exchange a few pleasantries with your colleagues before getting down to business.
Pay attention
Do not use your smartphone unless everyone knows that you are looking up something pertaining to the meeting. Do not fiddle with your paperwork while someone else is speaking. You should already be familiar with your documentation before the meeting starts. Avoid any conversation/whispering with your neighbor or anyone else in the meeting. Anything you have to say must be directed to the meeting host. You can speak if you are directing comments for all the attendees to hear. Sit up. Look alive, alert, and awake regardless of how bored you may be.
Participation
Listen carefully to everyone who is contributing to the discussion. Then look for an opportunity to join the conversation. You were invited to the meeting for a reason. You are there to either learn something or to share your knowledge. Or both. If you are there to learn, then ask relevant questions. If you are there to share information make sure it is accurate, complete, and to the point.
Productivity
You must make an effort to take away something from the meeting. You may learn something new about the industry, company, client, or your coworkers. The meeting may not go as you expected, but it was an investment of your time. You must have something to show for that. You will leave the meeting informed and should look for opportunities to share, implement, or apply this knowledge.