If you're anything like me, you have someone you're constantly writing for. Your first reader, your muse, the only person who truly understands you.
For me, that person is my fiancé. He has read everything I've written. He's laughed, he's cried, he's applauded my accomplishments, and taken apostrophes out of more it's than I care to mention. In the beginning it was hard for me to give him any of my work without meticulously pouring through it. I would make sure it was the best it could be so he would only be able to say this is great! Even though he never did (there are always improvements) nor would I truly want him to (because how else would I get any better) I still strove for perfection before handing any manuscript off.
This is as it should be.
As I've become more comfortable with him reading my work, I've become looser about giving him work-in-progress pieces. I've been churning out so many stories in such a short time, that I'll rush a piece to him just so he can look at it before he goes to work. I depend so much on his opinion that I have come to believe that the faster I get his edits, the faster I'll be done with the story.
The opposite has proven to be true.
When I get his opinion too early in my process his words get clogged up in mine. I can't see the piece I wrote anymore, I see the piece he wants me to write. I lose my vision, I get caught up in grammar, the spelling, the notes, I get lost along the way.
Writing is a solitary endeavor for a reason. A story can live in your head, boil over and over for years, and you won't know what it all means until you get it out on paper. Even then, it takes draft upon draft to notice the idiosyncrasies, the themes, the delicate undertones you're trying to express. The writer weaves, the reader unravels.
If the work is not tight to begin with, the reader will pull at its loose threads and tear it apart.
When you hand a reader a manuscript and tell them to edit it, they always will. Even if it's Moby Dick, or The Bell Jar, or A Prodigal Summer. Hand a reader a novel that's bound and published, and say here's my story, chances are, they'll have nothing to say.
Opinions fly at the writer from all directions, and it's the writer's job to decide which ones to consider. Ultimately you have to be content with the piece before it's shared. If you bring another person in too soon, their opinions, good or bad, will hinder your process.
Be true to the story, and satisfy your own eye first. Tighten and rework until your story is perfect. Then and only then should your first reader be allowed to take a peek.