Clark blushing.
Granted, it is canon, since Tom does blush quite a bit on the show, but he doesn't blush every time someone looks cross-eyed at him, people!

Lex goes on a drug and or booze bender and (insert Smallvillian here—Clark, Lana, Whitney, etc.) discovers him, helps him to his room and wham, they wind up in bed together.
Lex does drink, but we haven't seen him drink himself into an absolute stupor. As best we can tell, Lex is a young man in perfect health—at least, as long as he's been in Smallville—he doesn't strike me as the sort who wants to waste his 'second chance' in Smallville, getting plastered.

Chloe Sullivan is Lois Lane
Yes, the letters l-o-i-s l-a-n-e can be found in Chloe's name. Yes, they are both intrepid girl reporters. But there's a little too much "Chloe grows up, dyes her hair, and changes her name" fiction out there right now. I'm as much of a Clark/Chloe shipper as the next gal, but I think that it's pure wishful thinking.

Clark tastes minty.
Sure, in Hug. But all the time? Like it's a natural Kryptonian physiological thing? Every time anyone kisses him, they are struck by the taste of Crest toothpaste? Its over-use in fanfic has made it a cliché.

Lana looking "caught in the headlights."
Yes, it happens a lot on the show, but any subtlety this facial expression has is lost when it has to be described in four or more words... and reading it over and over makes the reader exasperated with the character.

Chloe Sullivan is addicted to caffeine
Because this worked very well in several very popular stories, it's beginning to crop up very frequently. Proceed with caution.

Using rape/incest as a plot bunny to get two characters into bed
First off, writing about rape or incest without doing the proper research can trivialise a very serious subject, and can go beyond tacky into the genuinely harmful. Particularly regarding eroticising rape. But secondly, it's important to think about the ramifications of that choice. You do the characters a tremendous disservice, but more importantly, if used as a cheap device, you are doing real-life survivors a tremendous disservice. And that ain't cool. And thirdly? We already know Magnificent Bastard (aka Lionel) is a, well, magnificent bastard. Why demonise him even further? Likewise, turning Whitney from jerk and jock into a rapist just to facilitate Clark/Lana, or Clark/Lex is a bit of a stretch. Why write an opera when a simple ballad will do? It's just wratcheting up the angst to facilitate the comfort part of h/c.

Lex is completely hairless. All over.
Guess again. Lex has eyebrows. And eye lashes.

Lana being written as a bitch in Clark/Chloe stories. Or Lana and Chloe hating each other.
While the season began with Chloe snarking about Lana as a member of the "pom-pom brigade" and generally ragging on her, ever since Lana came to Chloe to ask her to get a copy of Laura Potter's graduation speech, the two characters have forged a friendship. Particularly after Lana went to bat for Chloe in Rogue with the Torch. At the very least, they have enough of a friendship that Lana accompanied Chloe on a sleuthing expedition in Nicodemus.

Lex bursts into tears and confesses all his secrets to Clark/Chloe/Lana/Martha, etc...
Lex has never, to my knowledge, cried on the show. If he's upset, he's more likely to react with anger (ex. throwing the rapier into the wall in a fit of irritation in the Premiere).

Clark kisses Lana/Lex/Chloe/Whitney and then confesses all his secrets...
Love is a wonderful thing, but the boy has to be smarter than that. His father hasn't spent 12 years pounding the need for secrecy into his head for it to go flying out the window once he starts dating someone.

Clark drinking from the milk bottle and Martha chastising him for it.
It happened twice. Please, let's keep it that way. Find another way for Martha to snark on how Clark learned manners.

Characters kiss for the first time, and immediately profess their undying love for one another
Just a little too simplistic, and it's become a cliché, which particularly doesn't seem valid for Lex at all...

Whitney constantly being portrayed as some evil jock set to cause more trouble than Lex.
I know that he stood in the way of Clark and Lana for the whole of the first season, but most of the time Lana didn't mind. At worst he acted like an idiot when jealousy got the best of him, he's actually never been anything more than a nice kid who's gone off the rails a few times due to circumstances.

Clark's skin is always warm/hot to the touch.
While Clark did say in Cool that he did not notice/feel the cold, there has yet been no evidence that his actual body temperature is any higher than a normal human being's, or that he is abnormally hot to the touch.

Pete likes girls!
Why yes, yes he does, but when that's his only purpose in a fanfiction, it gets a bit old. Yes, Pete chases girls on the show. Yes, he does it a lot. But please, give the boy something constructive to do if you're going to have him in your story.

Clark saying that he cannot drive a standard transmission vehicle (stick shift) as a faciliator for Lex to teach him how.
Being a young man growing up on a farm, it's highly unlikely. My brother (the oldest in our family) could drive stick by the time he was 11, mainly because Dad needed him to run the farm equipment, such as tractors, which are mostly standard transmission vehicles. That being said, I don't think Clark, as an only child in a farming family, could make it to 15 without learning to drive said farm tractors. And that means that he can drive a standard transmission car/truck. Without Lex's tuteledge. And no, contrary to what any "city slickers" might say, tractors are not so different than cars when it comes to the stick shift. Cars and trucks have a couple more gears is all, but the concept is the same and only a total brain dead moron could not drive a stick shift car and yet still drive a tractor. Clark's not a moron, nor is he brain dead. He can drive stick.

The satiny, silky, smooth perfection of Lex's skin. All over.
Nice image, but c'mon--the guy is more than just his epidermis. Oh, and (similarly) there's an overuse of the word "pate" in connection with Lex. Understandable, but still...

Virginal Clark as Sex God.
You know what? No one having sex for the very first time has a romance novel perfect experience, replete with simultaneous and/or multiple orgasms. No one. It's messy, it's awkward, it often involves not getting things in the right place, or being able to keep them in the right place, and it usually involves at least one load of laundry. Please, reality can be just as sexy as fantasy, if handled correctly.

Seen it all? Want to help new writers avoid the same-old same-old plot contrivances that drive you mad? Share your fan fiction clichés!