You've brainstormed, outlined, and written your first draft. Now it's time to critique your beta version. (Not sure how I turned this informative blog series into a "you" but remember these methods apply to anyone critiquing a work, and yes, you should be critiquing your own work along with any others that do so.
So Beta readers. Usually for beta readers you want to focus on readers, not so much writers, though there is nothing wrong with using writers as betas, just remember that each of these phases requires a different hat to be worn, and all your beta readers need to be wearing that hat.
And writers usually became such because of their love of reading, so don't forgot, writers are readers too.
Anyway, by now your story should be pretty solid. Your plot should have a beginning, a middle, and an end. Your chracters should learn something, and use that knowledge to save the day.
This time it's about polish. This is a good time to worry about those little details with punctuation (though you should be running your works though Word's spell checker at a minimum before you ever send your manuscript to anyone, so by now it should have been spell/grammar checked at least twice.)
But mostly in this phase you're looking for flow. Are the emotional beats in their proper locations? Are the readers genuinely surprised at the villain's twist reveal? Are they terrified that the couple won't be together at the end?
It helps to have people who have never read the story before to read it now. Also have people who have read it comment on things they thought changed for the better.
As a critiquer though, you should be caught up in the story and only mark down whenever you are pulled from the story, and mark down why you were pulled. A good author will ask specific questions about the work too, probably broken up by chapter, and ask specific questions about that chapter's emotional flow, reveal, action scene, or twist.
This is the final stage to get the content of the story correct. After this it's all about polishing, presentation, and packaging.