I realize not all of us have the freedom to do whatever we feel like doing all day at work. But assuming you have some wiggle room on what you do and when I find letting your mood dictate that is a recipe for a productive day.

I have a variety of things I can be doing that I’d consider productive:

• Coding
• Emailing
• Organizing
• Designing
  
• Writing

And, being a human being, I have a variety of ways I’m feeling. There are infinite ways I might be feeling, but to boil it down to some large practical buckets:

• Fresh
• Average
• Tired
• Toast

If I was going to pair up those activities for me, it might be something like:

• Fresh: Writing & Emailing
• Average: Designing & Coding
• Tired: Organizing 
• Toast: Go home

I’m not good at writing (email or otherwise) when I’m not quite fresh. It’s mentally taxing, and the stakes for how well I do it are high. I’d rather capture my most energetic and fresh moods to do writing. 

Once that has worn off, I can settle into regular tasks like designing and coding. Once I’m pretty wiped, I can do low-effort low-stakes tasks like organizing and cleanup. I might knock off the easiest emails that require no written reply. I might organize my todo lists. I might clean up internal documentation and planning documents and calendars. 

Then once I’ve really had it, I gotta just shut the laptop. That used to be harder, but I’ve gotten better at it. I suck at everything when I’m super tired. I imagine most of us do.