When you have several meetings packed into one day, you almost always end up with gaps between each one. Even though these gaps are often about 30 minutes, they seem like they aren't long enough to get anything done. Keep an ongoing list of small tasks to make the most of them.
Image from francisco_osorio.
When you have small tasks that take 30 minutes or less, or can be done in 30 minute stages, create a list so you can easily see what to jump into next. If you're tackling a project that can be done in these 30 minute stages, use a personal kanban to keep everything even more organised.
If you have an even shorter break, use the time to take care of your "10 minute daily tasks." Of course, there's nothing wrong with just taking a break between meetings to decompress and mentally prepare for the next one — so if you need to do that, go ahead and do so.
Don't Waste Those 30-Minute Gaps Between Meetings [Harvard Business Review]