My observations about how some authors sound.
Sound Like You
Do you know what I hate? People who write like they've just swallowed a dictionary. In most novels and short stories you do see more formal writing than you would get in normal conversation, and that's just the way it is. Over my years of reading I have poured over the Webster's Dictionary more often than I'd like to think of trying to find out what some authors are talking about. Just from their writing I know that these authors are probably not someone I would feel comfortable sitting down and having a conversation with, and this is something I consider when deciding whether or not to buy another book by an author. Here are a few things that any author should know when writing their books or stories about how to sound.
Real people use contractions in everyday speech. I see no reason not to use them in novels. Using contractions makes the writer and their characters sound like normal people.
Similes and metaphors are effective in writing. They help paint a picture for the reader of the setting, the appearance of the characters and their emotions, as well as many other things. Don't, though, get too flowery with these techniques. Use comparisons that most people will recognize. I like to use some of the expressions I hear people in my own life use every day as similes and metaphors: brazen as brass, as big as all outdoors, just to name two.
It sounds nice to use words which people have to look up, but are you really impressing your reader? The answer to this is probably not. My vocabulary has been expanded with all the books I have read over the years. But, it did get aggravating when time I could have spent enjoying the story was spent running to the dictionary. It is okay to use words that many people know the meaning of. Long words could be used in dialogue for a snobby person, to bring that character trait out.
I am not saying to sound uneducated or stupid. I am just stressing that many readers might want to feel like the authors they read are someone they would want to sit down and have coffee with.