I've started to introduce more main characters, and am having a hard time thinking how these new characters act and think. The main character's mindset has been based loosely off of my own (what would I do?), but I'm afraid if I stay within the realms of my personal experiences and opinions, all of my other characters will become essentially a different looking copy of the main character. How do I think beyond how I think?
Nothing wrong with doing that at the beginning. It's not as if your audience will be able to tell unless they've met you. If you're really unsure, take baby steps. Introduce a few aspects that are different and then go from there with future characters. Or you could embellish one quality to the point where it doesn't look like you but you still understand it. Little things like this can make a huge difference it making sure the character isn't a carbon copy of you, But if it suits what you want and what the story needs, why not have a character similar to yourself?
There are also many question sheets to fill out, that force the author to answer questions about their character. Once answered you can see exactly if/how you'd like to change each character.
My process is to ask myself What is the purpose of this character in my story? Remember that a story is about the people within that story. Everything else is just stage-props and special effects. So, when you introduce new characters to the story, you have to ask yourself what purpose will they serve. Are they there to introduce the conflict? Are they there to help resolve the conflict? Are they a symbol of some other small idea that you would like to imbed in the story? Are they a representation of faith, or the lack thereof? The answer to these kinds of questions, for there are countless other questions that come from the same set of questions, will lead you to the mindset you need for the character. If you don't know why a character is in the story when you start to write this character, then the real question is What is this character doing taking up page space?
