Writing Voice

I wanted to do a piece on writing voice, because it's something I'm very aware of in the stories that I write.
There's of course, the writer's voice, their own, individual style that makes a story so distinctive, and has us all reaching for the next Nora Roberts or Jeffry Deaver.
But within the bounds of the story, there are each character's individual voices - and writing them properly is something that I think it's always worth focusing on.
When I'm writing romance, I write in third person pov, and write approximately half the manuscript in the heroine's pov, and half in the hero's. In movies, we're constrained by language. Everything that the character feels and thinks must be conveyed through action or dialogue, or lack of it! Wonderful actresses and actors who can convey the unspoken with a look can really make a film or a tv series - I've blogged before about the female characters in The Good Wife, who are definite masters, or should I say, mistresses in this.
When I'm writing, I need to remember that each character should have their own voice too.
Their voice is different to my author voice, although of course, my voice comes into it as I weave the threads.
Here's an example:
When I'm writing a hero, it's easy to keep his dialogue authentic. After all, it's the spoken word, and reading it aloud will usually tell me if I've done it right. But I have to carry that further, into his thoughts, his ruminations, and the narrative told in his viewpoint.
Say he's faced with a beautiful heroine. It's tempting to rave about the glints of sunlight in her hair, the deep azure of her eyes...to wax lyrical. And as a writer in love with words, I have to keep an eye on this, and make sure I don't do it.
He's much more likely to appreciate her in his own way...in thoughts that match his dialogue, express his feelings in a male way rather than a female one.
So how do I keep myself on track? At the end of the first draft (I don't stop when the flow is flowing!) I highlight all the text in the ms that's written in male pov, and read it. I try to think like my hero. Try to make sure everything rings true to the man he is, the way he thinks.
I find this really useful. It means my story has (hopefully!) more than one voice, and the hero's distinctive personality shines through.
What do you all think? Writers, do you do something similar? And readers, does a story jar if thoughts seem to be expressed in a way that is out of character?