Internalization: the first step to creating deep, believable characters

No matter how fabulous your plot...

how beautiful your language...

how incredible your world building...

no matter how many explosive action scenes...

or daring twists and turns your novel might contain...

...it is destined to fall flat on its face if it does not have characters that your audience can connect with.  Character is essential, because it is the human factor.  We relate to characters, even when we can't relate to the world they are in.  Even in fantasy, sci-fi, and paranormal settings that are completely foreign to us, we are still anchored to the world through the characters.  Even in an explosive action flick, we don't give a damn whether or not the characters die if we don't connect to them.  (Raise your hand if you've ever read a book and you've been like "Wow, I really hope this character dies.")  *Raises hand*

There's a lot of advice on building character out there.  I would suggest a take-it-or-leave-it approach on all writing advice (including mine), because not every writer works in the same way.  You have to do what works for you.  But since the comment I get the most about my book is something to the effect of "the characters are amazing", I figured I would share my personal process with you.

Internalization.  It's as simple and as complicated as that.  No worksheets, lists of favorite colors, or anything of the sort.  Just large amounts of time staring into space.  A realistic character grows out of the author's empathy.  You have to be able to put yourself in that character's place-- to become the character, in a way.  You have to move beyond knowing about the character, and actually start knowing the character.  There is a huge difference.  (It doesn't involve favorite colors.)

So how, exactly, do you do this?  Basically, it's professional daydreaming.  Imagine your character, put them in a scene, and let your mind run wild with it.  I do this without writing it down, because I feel that words can get in the way at this point.  I am more concerned with seeing, with understanding.  Many, many times the scenes I imagine do not happen in my book.  They may take place before, but often they are 'alternate realities'-- an outcome that would happen if the tiniest detail were changed.  I run through countless numbers of alternate scenes until I am satisfied.  I edit out nothing, make no attempts to reign my characters in.  I let them be what they will, and see what happens.  As for the scenes themselves, I go where my mind wants.  Something that I feel sucked into.  Usually something with deep emotion.  That's where I find the most useful information about my characters.  Sometimes I learn about things they might keep secret.  Sometimes I learn about past traumas.  Sometimes I learn important things that would happen if my world had allowed it, and the insight gleaned helps me understand reactions to things the world does allow.

This is by no means the full scope of character development, but I would recommend giving it a try if you have never worked like this before.  It is a really good starting place for getting your characters out of the can (no one wants canned characters for dinner) and helping them to glow with real life.

OK, one last thing:  Don't just do it for your main character.  The more, the merrier.  Take time to know all your characters, and BAM, your writing just got so much better.