10 ways to look like a 'newbie'
7. Want syrup with that waffle?
New writers invariably give themselves away by saturating their work with irrelevant waffle. By flooding the reader with background information. By waxing way too poetic. If it doesn't move the story along or if it doesn't contribute to the characters development, leave it out. If the present action, dialogue or narrative doesn't naturally lend itself to a few lines of drip-fed backstory, then chop it. It's probably not that important.
Closely related to this is being a smart arse in print. Just because you're clever enough to write a book doesn't make you cleverer than your readers. Don't drown your poor reader in the finer details of the history of square dancing just because you happen to know it. If its not relevant to your story then... save it for a marketable non-fiction on the origins of dance.
In fact, even if it is relevant to your story try to be judicious in your application of the specialist knowledge. Do your editor/agent/reader a favour and remember the adage "less is more".