Every plot needs a good character to move the story along. But how do writers create characters? Well, I don't know about other writers, but my style is more plot oriented. I come up with a plot to the story, and then I create a character afterwards to make that plot move along.
For example, if your plot has to deal with killing monsters and vampires, then a kick ass slayer type of character is what you need.
If your plot is about a war of wizards, then maybe an ordinary kid who later becomes a powerful wizard will be the right character for your book.
!Alert! : Creating characters just to move a plot along can make your characters really passive. Readers want to read about a character that takes an active role in the story. So you must develop your characters until they can move around on their own, even if you take the plot away. (This is one of my weak points as a writer. My characters tend to be on the passive side. But I'm learning).
Another way to create characters is to just use a stereotype. There is nothing wrong with using stereotypes in a story. I know that it's a cliche, but some authors do it all the time, especially if they have to write about tons of characters.
For example, a few of JK Rowling's characters in her series, "Harry Potter", are stereotypes. Like, the gentle giant, the wise old man, the comic relief, the friend who would betray, etc... Those types of characters could be found in many other books.
However, I'm not saying that Rowling's characters are just stereotypes. They might have started out that way, but since Rowling is a master at character development, her characters have grown out of the old cliches and become so much more. So a good starting point in creating characters are by using stereotypes.
These are the two methods that I use to create characters. The characters in my novels were created after I made my plot. And some of my characters are just stereotypes, like the goth, the jock, the spoiled rich girl, the comic book geek, etc... (this sounds like the setting of my story is in a high school, but it's not). However, my characters have evolved over the months and years since I first thought of them. And I think that they're great characters, except for the one that I'm going to kill.
So happy writing to all you writers out there,
P.S. - After awhile, the characters kind of come to life on their own. Their personality starts to evolve and break out of the stereotype, little by little. But that's okay. Sometimes this could make your character more real and dynamic. So don't try to restrain and force them into the image in your head. You'll be fighting a losing battle.