Always be sure you're using the right word. If you're not sure, don't use it! Here's a great list from Woe Is I.
Mary, Mary, quite contrary, how does your garden grow? With prose that sells, and no misspells, and smart quotes all in a row.
This is a nifty little neologism, and here is Rosenthal's piece (link to: http://www.nytimes.com/2009/09/27/magazine/27FOB-onlanguage-t.html?_r=1), which offers numerous useful examples. Among them: enervated, which means "weakened," not "energized," and fortuitous, which means "by chance," not "fortunately." Rosenthal cites seven others: fulsome, noisome, enormity, disinterested, penultimate, presently and restive.