Some authors claim that characters live in the their head, sometimes ignore their directives and even argue with what the author has planned for them to do. The difficulty with capturing real characters is the finite number of words in a book. The reader has only a short period of time to become acquainted with the character before the action starts.
There is an easy way to do this. Describe the main character as a tall, muscular, fearless, and impatient man that speaks four different languages, has a preference for blonds and BMWs, and a severe allergy to peanuts. Then, there is the better way–write the narrative in a manner so the reader can observe the character, follow what he does, see how he reacts, hear what others say about him, and even listen to what he thinks about other characters.
The next challenge is embellishing all the other less important characters, which is necessary unless you are writing a new version of Robinson Caruso. You cannot create them all with the same detailed development reserved for the main characters unless you want to drive your readers up a wall. Simply naming each character is confusing. We only want to spend the mental energy to keep track of the names of a few major characters and their sidekicks. Each minor character who is seen repeatedly should still have a bit of individuality, like a quirk in behavior or a physical trait to make them distinguishable from the others.
So here are some usable shortcuts to creating characters:
Archetype–the embodiment of a collective set of characteristics for universal types of humans. Archetypes include the mentor, a wise old man or woman willing to share their wisdom with the hero, or the trickster, a lively character whose loyalty is always suspect. Archetypes must be fleshed out with details to make them unique and different from other characters who are the same archetype, otherwise they are simply a stereotype.
Doppelganger–a character who looks identical to a main character. The doppelganger can be an empathetic companion or an evil twin. Technically the doppelganger is an archetype, but their traits may be the same or opposite of their spitting image. They don’t have the boundaries of other archetypes.
Foil–a character who is pretty much the opposite of another, usually the protagonist. For example, a clumsy, shy foil would make your protagonist seem suave and cosmopolitan.
Semi-round character–a partially developed character that has a contradictory trait or two to keep them from being flat and boring, such as an actor with stage fright.
Creating complex characters for the protagonist, the antagonist and their cohorts is usually both more difficult and more satisfying for the writer and the reader. Of course, some readers would rather simply be told what each character is like and they actually enjoy major characters who are stereotypes. Flat main characters are predictable and do not require any close observation or deep thought while reading. As a writer you have to decide who you are writing for and if you can live with your decision.