One of the most powerful ways to streamline a meeting is to skip it all together. 

As this article from Harvard Business Review makes clear, most meetings are not well conceived on the outset and suffer from a failure to prepare properly. When we really consider the objective of gathering together a group, we often discover we can reach the same goal without disrupting everyone. Remember that meetings are high-cost for time and attention and need to deliver a high return on that time to be worthwhile - to both the company and everyone participating.