I have found that similes are very important. Especially They are like, allegories on the SATs where you compare something to something else. Good similes are especially important when you’re building a fantasy world. A properly executed simile can bridge the gap between the “real world,” and the world of of fantasy. A properly executed simile can liken a fantastic thing to a real world thing. For example, “The mermaid’s fin was as a blue as an summer sky,” can help the reader believe in mermaids because it likens something they don’t know, a mermaid’s fin, to something they do know, the color of the sky in summer. It makes the mermaid more believable. I have also found that if I use too many similes, it can make the reader slog through the pages of a story like a muddy swamp. Wow! that was a good one! Anyway, similes should be used sparingly and with care.