In my limited experience, one key to successful standups is making them as small as possible. The worst standups are the ones which contain over a dozen people

In my limited experience, one key to successful standups is making them as small as possible. The worst standups are the ones which contain over a dozen people working on a bunch of only vaguely related projects. The best ones are the ones that only involve the people working on things directly related to thing I happen to be working on. I you're a manager this might mean that you have to organize 3 or 4 standups instead of just one and keep track of who is working on what and being sure the right people show up to the right meeting. If it turns out that someone is being blocked by someone not at the meeting then either set up a new meeting with just the people involved in that problem or make sure that particular person is at the next meeting.