When I was planning the first UK SINE, for about a month, I split each day into two.  I would get up in the morning, and do all the actions needed to move every bit of the project forward, cross most things off my to-do list and then add more.

After working on that for a few hours, I would sit down and think, "what actions do I need to take to move this project forward?"  Then I'd write those down.  I would collate my to-do lists and make a new one.

Then I would take an extended break - eating, relaxing, thinking, mapping.  When I was sufficiently rested, I would do the same thing again.  And so I would make 1 day into 2 days in terms of energy management and productivity.  And then go to sleep at night.  I only did that Monday - Friday.

That wasn't a sustainable way to live, but I only did it for a month, and boy was it productive!