1. Your protagonist should have either two best friends whom they share everything with or one best friend whom they keep in the dark about the new occurrences in their life.
2. The love interest in your story, if male, should be handsome and brooding. If there are two male love interests, then make the second one cute and cheesy. If your love interest is a woman then she had better be super hot because there are just no acceptable excuses for writing female fuglies.
3. There should be a mentor (old guy) in the story who knows everything but keeps it to himself. This is because the best guardians allow for heroes to make their own mistakes, even if it means that there is a good chance the hero will die in the process.
4. Gay characters exist for the sole purpose of pandering to heterosexual female protagonists. Have you ever seen a movie where a straight guy pretending to be gay applies lotion to a hot girl's bikini-clad body, gives his opinion on her outfits (while she undresses in front of him) and has her snuggle up close to him at night? That is because a gay man's sole purpose in life is to do all these things. Every straight female protagonist needs one!
5. You should accentuate protagonist's flaws by having an attractive and cruel character who signifies that being beautiful is synonymous with being mean. To balance this, you should also accentuate other characters' flaws so that the reader knows that your protagonist is average but not that average.
6. I'm sure you have a lot of cliché and tacky humour in you, itching to get out...but you have been told that clichés are bad. What you need is a scape goat character, who spouts these things and which make up his/her entire personality. Can be sidekick or minor character.
7. Your story needs to have at least one red-haired character but preferably more. Think red pigment is a recessive or fairly rare occurrence? Nope! Literature has shown us that gingers are everywhere. Add yours today.
8. If your protagonist's parents aren't on the young side (thirties or forties) then they should be dead or rarely appear in the story. No one wants to read about old people who once copulated to make your hero. Gross.
9. Remember to be politically correct and include different ethnicities in your story. Whenever you describe the skin colour of a non-white character, make sure that you use edible adjectives like chocolate, caramel or olive.
10. The best way to enrich your cast of characters is by using archetypes. A good place to start is the Major Arcana cards of a Tarot deck. Temperance? Your character is mild-mannered and always strives to keep the peace. The Fool? Make way for the overly-optimistic twit.