This is also the solution for developers. You sit down and do the work. Some days are better than others. If you have rituals or strategies to maximize that productive time, that's great, but don't sit around waiting for the muse to inspire you.

I find it helpful to have:

- resumable tasks - I want to sit down and work, not sit down and figure out what to do

- multiple projects - if today isn't a great day for intellectual pursuits and I keep getting interrupted maybe I'll do an admin task or fix some simple bugs. Also works for when something is stalled.

- acknowledge you cannot control everything - if the progress is delayed in ways the estimate didn't anticipate, document them and keep working