Yesterday I wrote about similes that didn't work for me. After giving up on the book I found them in, I started reading Framed by Frank Cottrell Boyce. He uses similes that I can't help but understand.
"Dr. Ramanan's car, for instance, was that deep red you only get on a Toyota. It looked like a big lady's fingernail."
"She's got two pigtails. That sounds nice and girly, but actually they make her look like a Viking."
Okay. I will admit that I have never seen a Viking in the flesh. But I have a cultural understanding of what a Viking is. Or was. Or at least an understanding of what one would look like. So I can take the unknown girl, Terrible Evans, and compare her to a Viking and get an idea of what she looks like.
Taken in the context of the paragraph, that second simile also tells us something about the character its describing that goes beyond her appearance.
I say that anytime you can make a bit of writing double its workload, go for it. Make those similes work like mules.