Here are ways to develop interesting characters. They are:
1. Find “different” personalities. These are characters that haven’t been seen in literature before, at least not often. The same rule applies to characters as to metaphors—trite is boring. Fast-One in There is a Generation is one of my favorites. I noticed her in a rundown cafe. What struck me about her was her sense of humor in the most decrepit and gloomiest of places. Even though our meeting was brief, her impression never left me. Why?—because she was unique.
2. Exaggerate personality traits. This works well for minor, single-facet characters because it’s an easy way to bring them to life. Be warned, however, consistency is a must.
3. Start outlandish and scale back. Think of the most bizarre personality imaginable and then reduce their strangeness to believability. By the way, for major characters, only two or three traits are necessary and, in most cases, workable. For minor characters, one or at the most two is sufficient. That limits how bizarre a character can get right there.
4. Input feelings from the writer into the character. Readers connect by empathy. When I began my first novels I wrote in third person, but my protagonist came out plastic and lifeless, so I switched to writing in the first person. This forced me to put my own feelings and reactions into situations. My main character came to life, as well as other lesser participants.
5. Use dialect if you’re familiar with it, but don’t overdo. Too much dialect is not only hard to control, but will eventually confuse and weary the reader, so be sparing. Plus the fact, in order for dialect to work well, it only takes a little.
5. Combine any of the above. However, for believability, remember, consistency is a must