Characters, yes, those pesky people that populate our tales. How do you make them real? The first step is to really know them. Ideally, you should know a lot more about the character than ever shows up in the story. Without a thorough understanding of your characters, how do you know how they will react, what they will say, in whatever nefarious situation your wicked imagination thrusts them into?
i have attached two tools i use. (Apologies for them being in notepad, i use an offbeat word processor) For a short story, you probably don't need all the questions answered. For novel length works, though, i have these completely filled out for all my major characters. They are at least partially completed for my secondary characters.