As an opener, I'd like to state that elves are certainly NOT cliché. It doesn't matter if they all have pointy ears, or they all live a long time, or even if they all like forests. It doesn't matter if they're short or tall or both. It doesn't matter if they're related to forest spirits or even angels. Regardless of how many elves are like one another or how many elves appear in how many books, elves are NOT cliché.
Why?
Well, for one, an elf is a creature. How can a creature be a cliché? Is a human cliché? They certainly do appear in a lot of books! How about dragons? Now there's a popular subject! Are dragons cliché as well? Well what about vampires too? Or werewolves? Or bats? Or rabbits? Or mice? Or owls? Or crows? Cats??