“Knowing nothing about fantasy stories and being unable to write a book myself, I am confident that I will be an indispensable book critic for you.” That's how my dad started off his critique. It made me laugh, which is a good way to start off with a critique.
I started a novel fourteen months ago. It's now totally written. I've revised it on a chapter by chapter basis and as a whole. There are still some things I want to change, but after a while it seems like it is a behemoth that is out of control. So I think I will quit were I am today and leave it alone for a week.
I know where I want the story to go, so I have been able to revise it quite a bit on my own. Also, my dad gave me a very good critique.
I am thinking more about revising because I am critiquing six stories/chapters for other people. Some of them are excellent. Some of them are strange. None of them are out and out horrible. Thank goodness. One of the stories is a chapter and I would like to read the rest of the book. Three of them are individual stories and all of those are a bit strange. One of them is “brain-warping.” When you read, you suspend belief. Well reading this is like suspending reality.
I tried to find something useful to say to each of them, beyond the easy grammar checks. I think I won't even mention those. They're on the work and they can read it themselves. When there is something really good, it is easy to say. When there is something really bad, it is easy to recognize and hard to say.
But one of these stories is just so weird I didn't know what to tell them. The story is well-written. There's a beginning, middle, and end. There's a major character and several minor characters. There's a problem and resolution. But it's whacked. The woman watches birds fly off with her children and then instead of running after them or anything, she feeds the damn birds. Everyone feeds the birds. There's no justification for it; it doesn't make sense. I was hard pressed to say anything useful to that person.
If you get a decent critique, you can revise easier. You know what did and didn't work for your audience. Even if there's only six of them. You get a sense for what is an individual problem and what is actually problematic in your work.
I teach and I'm having to critique papers all the time. Usually though they are non-fiction and the students have more of a vested interest in what I think and less in the words they put on the page. In creative writing it is the other way round.