Be your own harshest critic

As a writer, you have to be your own harshest critic.

You have to inhabit the role of a hyper-critical reader every time you write. You have to poke holes in your work wherever you can. You have to construct the strongest steel-man possible and confront the criticism it raises head-on.

You have to be brutally self-critical with your writing, because if you aren’t, the reader will (and because of the asynchronous nature of reading and writing, you will have no recourse at that point. The battle will be lost).