Metaphor vs. Simile

These two writing elements can be useful if used carefully.

• A SIMILE compares an event or object and usually provides a visual image: "It's like looking for a needle in a haystack." This example shows a simile that has become cliché. Best to avoid clichés.
  Here is a more original simile from a book I recently read: "maybe, like a dazzling supernova, I'll do something awesome one day."
• A METAPHOR replaces an occurrence or description with a figure of speech for which it is not literally applicable: e.g. nose to the grindstone, a cold fish feeling.

Problems can arise with both of these elements if they are overused or encompass too much of the text. The above-mentioned supernova simile was set up several paragraphs before the phrase with several space references intervening; by the time the "special" phrase arrived, the analogy seemed tired.