A few posts back; HERE. I mentioned how my female MC was bland, because I did not allow myself to go with my gut and give her flaws. I wanted the readers to like her, so I held a lot back. Now I am working on the rewrite and there were things there that I have jumped upon.
The main female MC has not had a "good" life. Her brother takes care of her, to the point that he pays her rent, gave her a job, and even buys her food. Why? Because she has been through a lot of trauma up to this point in her life and her brother really thinks it helps.
But how to show that she is a little unbalanced? In the first and second draft I did, I told the reader. This draft, I have found ways to show her mental state.
One was little physical ticks she developed. They were already in the story. I just picked them out and used them more. One was breathing through her hands when she was upset. Another was rubbing her neck with both hands. The last one was a surprise to me as a writer. I do not remember putting that in and thinking "This is a big one!" But when you find out a little of her past. That rubbing of her neck, is tied to a major event of her life.
Minor characters are starting to be fleshed out more. The aforementioned brother, there are reasons for his mother henning of his sister. Reasons that were not clear before. And his girlfriend, a bit of a bitch, but the type of bitch most women respect. The type that speaks her mind, without putting people down. All this came out in new dialog.
So what I am learning is that you don't have to force your characters personalities to appear. They are there already, you just have to coax them out. A little dialog here, a reaction there. All of it helps to make interesting characters.