Specificity about objects, emotions, and characters creates startling, fresh fiction. The details should be pertinent to the character and mood of the work.
Vagueness and cliches suck all the lifeblood out of your fiction, like a condor-sized Alaskan mosquito. (See how it wasn't a vampire, there?)
"Tyler gets me a job as a waiter, after that Tyler's pushing a gun in my mouth and saying, the first step to eternal life is you have to die. ... The barrel of the gun pressed the back of my throat, Tyler says, 'We really won't die.' With my tongue I can fell the silencer holes we drilled into the barrel of the gun." (Fight Club, Chuck Palahniuk)
Wow. That's a specific detail.
"Lyme Disease?" "Spread by tick bite. They're seething in the grass. You get Bell's palsy, meningitis, the lining of your brain swells like dough." ("Modern Love," T.C. Boyle)
"ABANDON ALL HOPE YE WHO ENTER HERE is scrawled in blood red lettering on the side of the Chemical Bank near the corner of Eleventh and First and is in print large enough to be seen from the backseat of the cab as it lurches forward in the traffic leaving Wall Street and just as Timothy Price notices the words a bus pulls up, the advertisement for Les Miserables on its side blocking his view, but Price who is with Pierce & Pierce and twenty-six doesn't seem to care because he tell the driver he will give him five dollars to turn up the radio, 'Be My Baby' on WYNN, and the driver, black, not American, does so. ... Price calms down, continues to stare out the cab's dirty window, probably at the word FEAR sprayed in red graffiti on the side of McDonald's on Fourth and Seventh." (American Psycho, Bret Easton Ellis)