When things don't go according to plan, "chill!", says Cvijetic.

From the original post:

"Even if you become an expert in productivity and time management, you will still have a lot of inefficiencies. This is usually because we often depend on external circumstances. If I schedule a meeting and someone is late, I just take out my kindle or podcast and make sure to use that time efficiently. And breathe."

I think everyone can relate to this. You arrive on time to a meeting or appointment, and the person or group you're meeting is late. So you sit around idly, counting the minutes of precious time that you're wasting while sitting here waiting to get started. Why not make use of this time?

Learning how to make the most of every single minute of my day (especially those unexpected moments of "free time") has been key to upping my productivity levels.