If you’re highly productive then you most likely have systems.
Systems enable you to do certain kinds of things … systematically.
Specifically, there are certain kinds of things that happen all the time.
Thus, if you have a system for dealing with them, then you don’t have to reinvent the wheel all the time.
This seems obvious yet in practice, I fear that most of us don’t realize just how many things we’re not systematizing … and in not doing so, wasting countless hours of precious time.
One obvious example right off the bat: email.
You probably get a lot of email.
You probably check your inbox(es) frequently.
You probably don’t have a polished system for checking, reading, and responding to them.
This is, potentially, a deadly time killer.
Here’s one excellent system for managing email.
It’s not the only one out there, but it works.
The Healthy Path 
Very sensible to have a system for managing emails. I could do with developing my system further 🙂