If you've been reading my blog, then by now you've already learned how to create characters. If you don't know how to create characters, just click here for my blog post on the subject.
Now that you made your characters, you will now need to know how to develop them. Before, I used to think that the most important thing in a story is the plot. But that's wrong. Great characters are just as important as a great plot (and if you're writing in first person perspective, characters are definitely more important than a good plot). So be sure to develop and make your characters real.
Here are some methods that I use to help develop my characters so that they won't turn out to be flat and boring:
1) I fill out the Nanowrimo character questionnaire. They ask you questions about your characters, such as their fondest memory, their quirks, their insecurities, etc.... (they will also ask you questions about your characters that you will never mention in your book. You should answer those questions anyway because those answers will make the character more real in your mind, so you'll write them in a more dynamic way in your book). If you fill out this character sheet, your characters will become more real.
2) There should be flashbacks about the characters in your story. If one of your characters has a flashback, then that means that the character has a past history. This history will make your characters seem more real. For example, a husband and wife is talking about having children. In the next paragraph, there will be a flashback of that husband as a young boy playing by himself in the backyard. The flashback ends, and the husband tells his wife that he wants a lot of children. This shows that the husband is someone that wants a big family and doesn't want his children to grow up lonely like he did.
3) Write about your character in different situations. If you write a scene where your character is in a birthday party, or a maze, or sent into the future, or etc... then you get to see how your character will react outside of your story. A character shouldn't be a puppet used just to move the plot along. You've got to see how the character will react in different scenarios.
4) Create a short biography of your character from his/her point of view. Make your character describe the important moments in his/her life. Write it so that it seems that your character wrote it in their own grammer, dialogue, and tone that they would use. This develops the character's speaking voice, while at the same time gives you the character's history.
5) Keep in mind that if your character were to die, would your readers care if he/she died? (I recently wrote a short story in which the main character dies. I got someone to read it, and she cared more about what's for dinner than the death of that poor boy). To be honest, my best advice to teach you how to make readers care more about your character... is to read Harry Potter by JK Rowling. Those books can teach you a thing or two about creating characters that readers will care about.
So that's all the advice I can give you about character development. There are probably other tips out there on how to make your characters more real, but I can't keep procrastinating and look over every single article about developing characters. Sometimes the best way to develop your character is to just write down your story.
Happy writing to you all,