Before the meeting
Meeting preparation basics
A general misconception is that only the organizer needs to prepare for a meeting. (Although this is true for informational meetings where participants just sit and listen).
In most meetings where you expect a discussion between all participants everybody should be prepared.
Here are a 3 basic preparation rules for both organizer and participants that can avoid plenty of wasted time. You can tweak these rules and distribute them in your organization as general guidelines or convert them into a policy!
Meeting organizer
Rule #1: Do you have a clear purpose?
Do you have a clear purpose for the meeting that can easily be formulated in one sentence? If the answer is yes, go ahead and use this line as the meeting title. If the answer is no, you should not schedule a meeting but probably do some more research or you try to find another way to solve your issues(s)
Rule #2: Do you have a clear agenda?
An agenda is a road map of the meeting. It let you define the expected outcome and let your participants know what to expect and how to prepare. If you don't have an agenda, don't schedule the meeting!
Rule #3: Do participants have all documentation?
If you expect your participants to be prepared by looking at or reading over some materials make sure that they receive all materials well before the meeting and have time to review them. If you are too late distributing them, re-schedule the meeting or remove the affected items from the agenda!
Meeting participants
Rule #1: Is there and do you understand the purpose of the meeting?
If from the meeting invitation the purpose is missing or not clear or you think you should not be invited for that purpose, ask the meeting organizer for clarification (maybe there is good reason). If he or she cannot provide this, don't waste your time. Decline the meeting and remove it from your calendar.
Rule #2: Did you receive the meeting invitation with agenda in advance?
If you received a meeting invitation without a clear agenda you should simply decline the meeting. It's the organizer's responsibility to provide one and you should not waste your time chasing it. End of story!
Rule #3: Did you receive any documentation and did you review it?
The responsibility here is on both sides. If documentation is required but not provided, decline the meeting again as the organizer will be wasting your time. If the documentation was provided but you didn't review it, also decline the meeting out of respect for the organizer and other participants. You would be wasting their time!