One thing that (in my opinion anyway) a good writer must have is the ability to see the writing two ways simultaneously: as writer and as reader. You have to craft words and at the same time see them as though someone else crafted them.
Too much emphasis on crafting means the writer becomes precious, arrogant, overly assertive. This kind of writer is an editor's nightmare. Everything this writer produces is, in his or her not so humble opinion, Holy Writ. Not a word, not a comma may be changed. It's all perfect.
But too much emphasis on seeing the words fresh, as though written by someone else, means the writer will become frustrated, never achieving that perfect vision of the story a-dance in his or her head. This writer is over-critical, insecure, and discourages himself or herself in the long run.
So the balance is becoming bifocal. Part of your writing mind is the writer, planning and creating a balance of description, characterization, dialogue, action, and, oh yes, plot. The other part is the critical reader, constantly musing, "Is this the only way of getting this idea across? Would it work better as dialogue? Hmm. Is there a better, more precise word for what I mean? Hmm...."
It is a delicate act, to teeter between being too writerly and too readerly. Some people can't manage it and fall to one side or the other, which means they never can attain the success they wish for. Those writers who do are successful, for a given definition of "success." They publish and they are read.
Those who can hit and maintain the balance become great. And the secret to that is - well, between you and me, I just wish I knew.