1. Meetings must have a stated purpose
Meetings need a clear purpose to keep them on track and not waste people's time. What are we trying to get out of this meeting? When the purpose is reached, the meeting can end. Meetings should end with clear takeaways and next steps.
2. Presentation materials should be sent out at least 24 hours beforehand
If you're planning on presenting slides during a meeting, send them out beforehand. This way people can digest the material ahead of time and come prepared with their thoughts/questions and we can have a more productive discussion.
3. Avoid looking at laptops (and phones)
Bringing laptops to meetings can be useful since you might need to look something up related to the meeting. But it's tempting to use them to check email or do work that is unrelated. The lack of attention will waste people's time when you inevitably need to be brought up to speed (the exception being if you're not needed at the meeting in which case you can just leave).