A quick way to add depth to your story is to give your character a "flaw."
A more compelling way to define this, I think, is a "wound."
Because it's not really enough for a character to have this negative trait--there needs to be a reason for it. A good reason creates empathy, which is why we sometimes find ourselves relating to and understanding the villain of a story.
So if your character's "flaw" is that he has trust issues and closes himself off from relationships, the reason why is the wound from which this trait stems.
Maybe his girlfriend cheated on him. Or his fiancee left him at the altar. Or his wife packed her bags and walked out one day in search of a new life.
That event wounded him in some serious way, he hasn't dealt with it properly, and now a big part of his personality hinges on the idea that he's not going to open himself up to anyone for any reason whatsoever.
He's going to do whatever it takes to protect himself from being hurt again.
Enter a cute, spunky heroine and now we have a problem.
As your two characters circle one another, that flaw/wound is going to rear its ugly head at the most inopportune times.
But this is also going to open a pathway for growth and change. If, by the end of your story, the hero can move past his wound and open up his heart to love, he not only gets the girl, but your reader gets a satisfying resolution to his character arc.
This kind of internal arc is the foundation of all great romance novels, but even if you don't write in the genre, give your character a flaw that stems from a serious past wound, have them deal with it while they're dealing with whatever other obstacles you're throwing their way, and you have a nice recipe for a page-turning read.
Be Brilliant!
~Katie~
