Make sure you choose words based on their meaning and appropriateness, not on how:
For instance, I see the word “plethora” used all the time. “A plethora of choices!” exclaims a press release. The writer chose “plethora” because she thought it meant “an abundance of” and, perhaps, that it would make her sound smart. But “plethora” doesn’t solely mean “an abundance of,” it means, according to these dictionaries, too freakin’ many.
Even if you choose a word with the right meaning, though, what my third-grade teacher at Cleveland Elementary School in Skokie, Ill., used to call “$10 words” may, in fact, work against you. In the October 2005 issue of the Journal of Applied Cognitive Psychology, Daniel Oppenheimer, now at Princeton, published an article headlined “Consequences of Erudite Vernacular Utilized Irrespective of Necessity: Problems with Using Long Words Needlessly,” which explored students’ predilection for using big words to sound intelligent. He found that while this was common behavior, it wasn’t worth the time or effort.
"Anything that makes a text hard to read and understand, such as unnecessarily long words ... will lower readers' evaluations of the text and its author," he wrote, concluding, "one thing seems certain, write as simply and plainly as possible and it's more likely you'll be thought of as intelligent."
And, if you are going to use a $10 word? At least look it up!
Daniel Oppenheimer won a 2006 Ig Nobel Prize for his Journal of Applied Cognitive Psychology article; Ig Nobels - ignoble, get it? – are awarded to honor achievements that "first make people laugh, and then make them think."
By the way, when you do come across a word that you’re not familiar with, here’s an easy way to look it up if there’s no dictionary or computer nearby. Just text message Google at 46645, write “define:” followed by the word, and send (e.g., define:calyx). You’ll get the definition text messaged in return.