This isn't a problem just for novice writers either. Newspapers and magazines are filled with what I call "journalist-speak"––overly wordy phrases that have become so common we don't even question them. How many times have you heard or read the phrases "in the wake of September 11" or "the events of September 11"? Why use all those extra words when "After September 11" conveys the same meaning? Another one that drives me crazy is "the vehicle collided with a pole." Not only does the reporter use two words––collided with––when one––hit––will do; the word usage is incorrect. Technically, to collide both objects must be in motion. Unless the driver accidentally drove into the midst of some Scottish games, chances are the pole was not in motion.
Superfluous words can creep in when we feel compelled to connect sentences or paragraphs with words like also, however, though, because or phrases like "for example,""of course," "in addition to," "in fact." This is a mistake often made by writers of my generation who attended high school in the 60s and 70s. These days readers are used to making quick transitions in thought, so these words are often unnecessary.
In fiction the problem comes from writing like we speak. Telling my family history to a friend, I might say, "we would always go to the beach for the summer." In writing, "we spent every summer at the beach" or "we vacationed at the beach every summer" is much stronger and to the point. Another superfluous phrase is "used to" which is often a stand-in for "would."
I'm not immune to superfluous word use. While writing this I've excised several phrases like "in order to collide," and you'll probably find more in this and other posts, especially as I don't revise blog posts as carefully as I would an op-ed submission for my newspaper. I should point out, though, (an unnecessary though?) that using two words where one will do doesn't always render the additional words "superfluous." In fiction particularly, but also in article and post writing, it is equally important to vary sentence structure, because using only short declarative sentences can lead to very tedious reading. That varied sentence structure will often require more words, but those words will be necessary, not superfluous.
Superfluous words are empty words that, like empty calories, add bulk without producing energy. They weigh a piece down without adding anything of value. Next time you write something look for those words and phrases that may have become standard, but really supply no value or particular meaning. When you find them, throw them out.