How often have you been in this position? Unable to move a project forward because you want to do your best?
Best is a distraction.
Best is an abstract goal. It is impossible to meet because there are no concrete indicators.
Furthermore, best is a moving target. Future You will be a better scholar and writer than You Now, just as You Now is a better scholar and writer than Past You.
I strongly urge you to abandon Best. Your goal is to do good work. And then more good work.
You don’t have to strive to be better than you are. You will become a better scholar by practicing your craft regularly. You will become a better writer by submitting your work, receiving comments from reviewers, and revising your work. You will become a better scholar by publishing your work and moving on to explore other questions.
Trust that you can use the writing process to articulate your ideas. The first draft will be awful. It’s purpose is to get the ideas out of your head onto the page where you can develop them and make them clearer. You are capable of writing articulate prose. You are capable of sound scholarly analysis. Trust yourself.
Best is a distraction
At your retirement party, Future You can listen to others make a case for which parts of the body of scholarly work you created over your career are your best. Spoiler alert: they will all disagree on the specifics. But they will all agree that you did some great work.
In the meantime, do good work. Do it in a way that builds your confidence in your abilities. Do more good work.
Edited to add related post 25 August 2017. Related post links updated 25 October 2017.