My favorite part about writing fiction is being able to create characters; people who live only in the minds of the readers.
Whether or not a character I create is based on different parts of myself I make sure that they have their own voice and personality.
When creating new characters it's important that they each have their own fingerprints, or individual traits that, when put together, make each character unique. Two sisters, say twins, can't have identical fingerprints or it could get really confusing to the reader. Anyone who's ever been around twins knows that they often have the same voice and/or mannerisms, but there is always something about them that makes them different enough to their family and friends who can easily tell them apart.
You, as the writer, are responsible fer getting your readers close enough to your characters that they can distinguish one character from another without having to read their names.
1. Get to know your characters before you introduce them to other people.
When you introduce a new friend to your family you are saying, "I can vouch for this guy. He's a good person." When you're writing it's pretty much saying the same thing to the readers. If you don't truly know your characters then you can't, on good conscience, introduce them to the reader because you don't know if they'll turn out to be bad people (unless that's what you were going for).
You may be saying, "How could I not know my characters? I created them." That's true, but when you treat them like living people they become something more than words on a page. When you keep them internal then you are more inclined to put too much of yourself into who your characters are. I liken this to having a pet, a dog. Your dog can't talk to you but you still take the time to name him and acknowledge that he has a personality. When you talk to your dog you don't do it in your head. You actually talk to him, but don't expect an answer. Try doing the same with your characters. Project them outside of yourself so that you see them the way a reader would. Ask them questions that you would ask someone that you just met and wanted to get to know better.
Here's an example of how I question my characters. Character Interview
2. Get to know the people your characters know.
What kind of people do your characters associate with? Who are their coworkers? Who don't they get along with and why? These questions will help form a fuller picture of your characters personality type. It may also reveal your characters' morals, social status, and how they interact with other people.
3. Create scenarios for your characters.
Put your characters into situations, ranging from mundane to life altering, that occur before, throughout, and after the course of the novel or novella. How do they react? What did they do to get through each scenario? How did the way they react change over time? These will be the events that help shape their personalities.
You may have noticed that I didn't mention naming the characters. That's because I usually name my characters last. Sometimes their names are based on their personalities and other times they are just randomly picked from a name generator. There will be more on naming and generators in a later post.