His smile was a ghastly grimace. As wretched tears rolled down her trembling cheeks, she wondered if she'd ever see the light of day again. The knife blade was only inches from her pearly white throat. He laughed a maniacal laugh, his teeth tiny points of malice.
Oy. That was disturbingly easy to write. Those sentences are littered with adjectives/adverbs that are another form of telling. We get carried away by our own awesomeness, by the idea we can paint a picture with words instead of what isn't said. Let me say that again: what ISN'T said. The most effective writing is one that gives the reader enough info to populate his/her own imagination. It's a fine line and one that can years to perfect.
Let's see if I can demo this right off the cuff:
He grimaced so she saw his pointed teeth. Tears snaked down her cheeks, hot trails of fear fueled by the knife at her neck.
Far fewer words, yet a much bigger impace on the reader. Or so I hope. You'll have to tell ME which is better. (This is a subjective business, no?)
Now you try. :)