It doesn't matter what you write, what genre it is or target audience, there is always going to be hard parts of your stories. And I'm not talking about the parts that you get stuck on or the parts that just won't move properly, I'm talking about the gore, the grief, the heartbreak or all the torment we have to put our characters through. Writing about your hero and heroine breaking up, having to torture your good guy, or putting a character though loss and grief are hard things to write about sometimes, every author will tell you that, but writing them, will not only make you a better writer, but it will also help your story to have a stronger plot and stronger, more well-defined characters. What doesn't kill you makes your stronger, and characters go by that rule as well. A character with a good drive brought on by loss or hatred (or both) is going to move a book further than one who has never had anything happen to him in his life.
That doesn't mean you might not have to write these scenes with your eyes closed. Trust me, I have written scenes that have made me cry and stabbed me to the heart. There are scenes like that in the book I'm working on now, and yet, this is coming together as an amazing story with a wonderful cast of characters who I can't seem to get out of my head. Their pain and their drive drives me to write about them, even though some of the parts are hard to get through.
I've talked about torture scenes before, and yes, I know they are hard sometimes to get through, but if they add to the story line, then they need to be there! Perhaps your cocky hero needs to be maimed before he can realize what a jerk he's been. Maybe wounding your hero in the beginning of the book will drive the story along. Like Marcus from "Eagle of the Ninth". He was wounded in action, given an honorable discharge and because he was looking for reason, he went off to find what had happened to his father's lost legion. Or maybe take into consideration William Wallace (perhaps not so much from a real historical perspective) but a lot of fiction--Braveheart included--have the loss of his wife drive his decision to raise an army against the English. All these things hurt us to put our characters through but they need to be there, otherwise we wouldn't have plots that made for a good story.
Also, and this is something that hurts me above all else, there are times when you need to bring your characters low. Your hero might break down, they might even for a while give up will to live. These kinds of scenes tear me up, but sometimes they need to be there. The hardest part about writing these themes I think is being able to sell the grief. We might not have ever felt what we are putting our characters through and that makes it hard, but I find if you just kind of sit back and let these scenes write themselves, even if they kill you, then they work out for the best. And let us hope that your main guy's lass or best bud is there to help pull him through.
Typically writing romance, there's drama, (and this is why I don't usually like romance. I can't stand the drama!) but if this is your thing, then I suppose you're going to need to have your couple be stupid. Break up even though they know they can't live without each other or have something else come between them. These scenes are hard too. I think the hardest scenes, as I said before, come down to the emotional more than the physical though both can qualify for certain things.
This is for all you other writers out there: What are some 'difficult bits' that your struggle with and how do you overcome them? I'd like to see some of your input to this topic.