When creating fictional characters, it’s a good idea to think about their unique traits before plunging headlong into the story. Writing a profile for each character is really useful, especially if you are writing a novel. If you find yourself getting stuck, take a look at some of your favourite novels and consider just what made those characters so real to you. If you can identify this, you can add to strengthen your own writing.
Any character must feel real to the reader and once you have established how to do this, your story will have greater integrity and impact.