The trick with creative/narrative writing is to learn to show rather than tell. When it comes to character, sometimes we get hung up on telling the audience how the character looks and how the character feels rather than revealing who the character is through his/her actions and experiences (which is really how we truly get to know people in real life).
I think a good place to start is to think of all the different components that make up a person. You could begin by trying to define who you are as a person (or who your children or significant other are as people). Likely you will be overwhelmed with all of the different components that make you who you are (or what make them who they are). We have physical characteristics, personality traits, multiple roles that we play, motivations, thoughts, emotions, expectations, the actions we take, the ones we don't, and the ones we think we should have or should not have. Combined, these make a dynamic person that would be boring to describe all of the time but when revealed through action (i.e., dialogue, non-verbal communication, choices carried out, etc.) we have a realistic, intriguing, multi-dimensional character.
When writing a character, it helps to first plan out, profile, and picture the character in all his/her complexity to ensure that you actually have complexity. One thing to start with is to resist single-role/stereotypical characters that you can sum up in one sentence (i.e., "This character is the confident jock."). Instead, consider those paradoxes that exist in the people you have known through your own experiences (i.e., sometimes the people we meet who seem most confident actually have the most insecurities, or are only confident in certain circles or only about certain topics. Remove them from a situation, a group of people, etc. and they are completely different - thus, the person as a "confident jock" only makes up a slice of that character's full self. Perhaps he/she also has various anxieties, hobbies, dis/abilities, relationships, etc.).
What makes your character quirky? What makes him/her endearing? What makes him/her difficult to love at times? What is he/she proud of? What is he/she embarrassed about? What dreams or expectations does your character hold for him/herself? What motivates your character? What pet peeves would your character have? What personality traits does he/she possess? What experiences (traumatic, positive, etc.) has he/she had that really solidified or challenged those traits? Remember that it is okay (even good) to have conflicting characteristics (i.e., my character may be very patient with children but have a very short temper with strangers) as we are all contradictory from one situation to another. Check out this site for more questions you can ask yourself: http://www.writingforward.com/writing-prompts/creative-writing-prompts/character-driven-creative-writing-prompts
Once you've really thought about the dimensions of your character (and made some notes) you will want to put them into action. To reveal who your character really is (to show, not tell your readers) then you need to put them into a situation and see what they will do. Therefore, try the next challenge to practice showing your character's "self."
The Challenge:
Plan a character by thinking of the significant traits that make him/her a round, dynamic individual (you may already have one in mind). Show this dynamic character facing a moral dilemma in one scene. This scene may or may not include other people - it depends on what you want to reveal and how. Through the
conflict, reveal to your reader the character’s most significant traits. The character should interact and react with other objects
or people, the piece should not focus on describing the character physically.
If you don't know where to start with creating a dilemma or scene, consider what you know about your character (views on religion? political views? a fear? a naivety? an unrealistic expectation?) and try to create a conversation, a confrontation, an object, or an observation that would force the character to react (and thus reveal something about him/herself). If you still aren't sure, try out this site (under Creative Writing Prompts blue box) for interesting writing prompts that put your character in a creative conflict: http://www.pw.org/writing-prompts-exercises
If you don't know where to start with creating a dilemma or scene, consider what you know about your character (views on religion? political views? a fear? a naivety? an unrealistic expectation?) and try to create a conversation, a confrontation, an object, or an observation that would force the character to react (and thus reveal something about him/herself). If you still aren't sure, try out this site (under Creative Writing Prompts blue box) for interesting writing prompts that put your character in a creative conflict: http://www.pw.org/writing-prompts-exercises