One feature I have seen a lot on book tours recently are character interviews. This is an interview with a fictional character in a book.
Many books that I have seen have trouble separating the characters and making them different. I thought many of the characters in The Mortal Instruments series sounded alike, as are several in The Night Circus (even though I love that book for many other reasons). Douglas Adams and Orson Scott Card both have/had trouble giving different life to new characters.
It is a common problem, and can be hard to break through. The character interview can be a way to get around this issue and really try to identify the differences between characters. I like to do it like this:
Come up with a difficult situation, or maybe an everyday situation. The more situations, the better, actually. Imagine you are one character. How would that person react in a certain situation?
For example, at a party, would your character hang back or make friends instantly? In an earthquake, would the character be helpful or cause trouble?
It can also be helpful to create character profiles, or take an online personality test for each character in your story. I know a lot of people take personality tests for existing book characters, so why not for new ones?
What makes a character interview particularly helpful is how you can use it to actually alter the slang and speech cadence of each character. This is one of the hardest parts about character development, I believe, and many well-established authors still have trouble with it. Going through the extra trouble to really make each character come alive, however is worth the extra effort of digging into a character to make him or her into a complete person.
How do you make your characters come to life? What are your favorite ways to make each character different?