A novelist’s characters must be with him as he lies down to sleep,and as he wakes from his dreams. He must learn to hate them and to love them.
Well this sounds like fun at first, having a slumber party with your characters, until you realize you must hate them too. But yes, know your characters, know how they live, what they do every day in life, what their backstory is. I think I like that the best, because if you know them and they are real to you, there is no limit to their actions and your story will write itself, with the help of your outline and structuring to guide you. When I wrote my first novel I felt like my characters came alive. I had so much fun and it was so unexpected, too. I know your characters are to be flawed, so as to relate to your readers, that is the easy part as it happens so naturally that no one, not one of us, is perfect. Flaws are the easy part. You can hate them for that, or for the rotten things they do to each other. Either way you can.
I know it can be difficult to craft a character, but if you do your research, there are so many questionnaire lists to help you develop your characters that it can really get fun, and you can use one list for one character but another list might suit another character better. I really enjoy developing my characters, you can put some fun twists into their background and never say what it is to the reader, but it’s part of him! Or perhaps you can reveal this piece later in the series or toward the end of the work if you have resolved the piece of the character’s back ground.
Happy writing and it’s time for me to get back to my stories.