Be your own harshest critic

As a writer, you have to be our own harshest critic,

You have to inhabit the role of a very critical reader every time you write. You have to poke holes in it wherever you can. You have to be brutally self-critical with what you're writing, because if you don't do, the reader will do it for you.

And because of the asynchronous nature of reading and writing, you have no recourse at that point. The battle will be lost.