Unscheduled meetings can be more productive than scheduled ones.
This might seem counter intuitive so let me explain.
Some jobs involve doing lots of things at once. Or at least in very rapid succession. For example, a secretary really needs to know how to multitask. Other jobs are more "single threaded", like software development. They usually require a lot concentration, which means it takes a while to get into "the zone" and become truly productive. No programmer says "great, I have about 4 minutes free until my next meeting, let's use the time to do some programming". There's a ramp-up process, and it's really hard to enter this process when you know you're going to interrupt it very soon.
Enough theory, let's take an example. It's 9:30 AM and you have a team status meeting at 10:00. Are you going to start working on debugging that tricky crash, or are you going to pass the time with emails and make yourself coffee? You know it's going to take about 10 minutes just to warm up that cache that you keep in your skull, and there's nothing worse that having to stop in the middle of productive work. So you're not going to bother. You will procrastinate instead. StackOverflow. Facebook. Reddit.
If it weren't for that 10:00 meeting, you would have dived into work without hesitation. Regardless of how productive you think meetings are in general, all other things considered equal, you'd get more work done if instead of scheduling the meeting at 10:00 somebody would have just popped into your office and said "hey, got a sec to talk?". Scheduled meetings are a major source of procrastination.
Now granted, not all meeting can be impromptu. Some, maybe most, actually require preparation and coordination, so there's not much we can do about those. But some recurring meetings are just a way to catch up. Daily status meetings, morning Scrum stand-up meetings, etc.
The cure is simple. Don't schedule daily recurring meetings. Just let them happen. Let's say you're doing Scrum and this involves a stand-up meeting for 10 minutes every morning. If you schedule it for a fixed time-slot every time you're basically scheduling procrastination for the 20 minutes preceding it. So don't. Just wait until everybody's in and then announce "stand-up meeting in 5 minutes". That gives everybody just enough time to finish off what they're doing, but on the other hand there's no longer this meeting looming on your calendar each morning, making you avoid getting into any meaningful effort before it.
Don't schedule procrastination into your routine.