Each writer has there own distinct style. I'm sure there are a few (whom I utterly despise) that can sell their first draft. Few and far between. Most authors have to revise and edit and polish their stories several times before they send their babies to editors at publishing houses and/or agents.
For me, my rough draft is the meat and potatoes of the story: the dialogue and the action. Some emotions. But I tend to gloss over the descriptive parts of the story, the garnishes, the loaded aspect of the potatoes, the marinade.
Right now, I'm just editing Torn Between Murder and Love for content errors. Then I'll go back through it again and add in more descriptive passages and more emotion. The main character, Lorna, undergoes a big character change, and I have to make certain its believable, otherwise the story will fall flat.
I think some of the reason why I had a hard time adding description into my stories from the start comes from my tendency to gloss over the big paragraphs of setting and description in books. I love my imagination and I like to see the characters and the buildings as I want to see them, and since it doesn't always mash up with what the author says, I ignore the author. LOL Wow, does that sound narcissistic. But I honestly think that's where my problem comes from.
What about you? Is there any part of your writing that you have to go back and add? Or do you just tighten up and fix grammar when you edit?