I have talked about this in the past, but far too many submissions that I read are coming across as being forced. The writers are often trying too hard to do the "right things" or they are doing things in their stories because someone told them they should and not because it needs to be there. The result of this approach to writing is the passion behind the language and the voice of the author is simply not going to come through.
What you will find is that successful writers who seem to have a "knack" for writing are approaching their stories from an intuitive approach. These authors understand that the story and the situation dictates what should happen in the story. They understand that what the characters say and do is all going to change from one book to the next.
When we talk about intuition, we often think of the idea of being a gut instinct. You just know what needs to be done. This, of course, means you have to trust your writing and trust your gut to tell you what needs to be done in the story.
For many new authors, this is really a tough thing to understand. These authors are often trapped with thinking there is one way of doing something. They read blog posts on query letter and synopsis writing and think it is a 100% formula. They are often asking questions such as "You say you want stories that are 75,000 words but mine is 76,000 words, will you reject this?"
Intuition is simply listening to the words and thinking if these are the right things to say at this time. Is this really what would be happening in the story? If you are doing things just to get to the next point in the story, the odds are you are missing the whole intuition thing.
When I do critiques for people, I often get comments back such as "I had a feeling that was wrong." That is your gut telling you that a change probably should be made. You don't want to wait until an editor or agent says it is wrong. Trust your thinking.