For the longest time I relied more on my imagination and others experiences and less on my own when making up my fictional worlds and characters. I built stories on experiences I heard of second hand or witnessed from afar. And I copied from characters I had loved and people I'd found interesting over the years. Then I threw all this into big scenes in contrived stories I thought would be interesting to the masses.
One could argue that all these things can be good fodder for the muse, but it doesn't make a good end product. You need more. Because whats the point of having amazing stories and insane scenes, when the reader doesn't feel a thing for the 2D characters being drug through said stories.
People are the stories, or at least this is the notion I care about.
For me, it was putting more of my own self into the characters and allowing those characters to express some of my own universal concerns, my stories began to breath on their own. Giving our characters a piece of ourselves bonds us to them, making us care more for what we write--making us better writers. And in the end giving the reader a character deserving of their care.
Because in the end, isn't that what we all care about and connect with? The universal concerns, fears and dreams of all man.