So how do you avoid clichés and keep your similes under control? Nicola Morgan suggests that the simile must add meaning to the writing in order to be worthwhile, and points out that the entire content and connotation of the simile will be added (so be careful).
Question: what does that mean? What kind of meaning does a simile add?
My answer: two kinds.
First, a simile provides a comparison of a story event, character or object, with something else. As it does so, it lends all the qualities of that something else to the object (etc.) it describes. Here's an example, from my story "Smoke and Feathers":
...water reaches out over Ryuuji like a hand of glass.
What's happening here is that a boy, Ryuuji, is having water poured over him from a bucket. However, the effect of the water is far more than him getting wet. (I'll save that for those who read the story.) The simile compares the water to a hand reaching out, which gives the impression that the water could either grip Ryuuji, or maybe even cast a spell on him - things that hands, not water, can do. Thus when strange things start to happen afterward, we've already had a warning of it in the form of this simile.
Depending on the kind of word we choose to compare, the simile can bring along more connotations or evoke a more complete scene to go along with the thing that's being described. This is all included in the first kind of information that a simile imparts, through drawing a comparison.
The second kind of information that a simile can give us is character (and world) information. By this I mean, not comparing a character to something using a simile, but having the comparison itself reflect upon the person making it. If you are using point of view in your narrative, any simile you use will suggest things about the kind of person who would draw such a comparison. Here's an example that Nicola Morgan provided as being a bad example of a simile:
His words paralysed me. I was like a deer that's been transfixed by an arrow, right in its spine, so that it was alive but could not move. [The first sentence says it all. The simile simply adds some wholly unhelpful and, frankly, bizarre, extra images. We learn nothing extra and yet are bombarded with extraneous images of a dying Bambi.]She says that the first sentence says all it needs to and we don't learn anything extra. I'm not sure about that, though - I personally think the simile suggests something unexpected and unwanted about the character making it. The original writer probably didn't have it in mind to suggest that this POV character was sadistic, or obsessed with death, or anything of that nature. Yet somehow they did. There's added information here, certainly, but information which can only confuse readers about the point of view character.
The information that similes (and metaphors) give us about the point of view character is in fact extremely valuable, and I highly recommend you take advantage in it as you write. Think about what kinds of comparisons your character would make, and why. The comparisons they make will show readers how they judge a situation, and will reflect on their sense of themselves and their own world. Similes give us an enormous opportunity to add dimension and life to our stories.
It's something to think about.