Happy Friday the 13th! Gather up your good luck charms while ye may. I've got mine.
Have you ever had one of those arguments where long after it's over, you bolt awake knowing exactly what you SHOULD have said??
That's me writing scenes. Any scene. I've learned this about myself, though, so I give myself permission to write my the high emotion/high conflict scenes as pieces of junk first. They flow pretty easily because I know that overnight or in the shower the next morning, I'll suddenly get this brain dump of all the things I should have had these characters say to make everything much worse.
Yeah, but what about the scenes that aren't like that? *Shrug* I can't tell you what scene was hardest. Mainly because I get stuck so often. When I do, though, it is almost always because I can't see a way forward within whatever scene I'm working on. I get wrapped up in the back and forth between characters, but I may not necessarily be moving the story or conflict. That stops me every time, and I bog down.
To move forward, I have to walk away from the recalcitrant scene. I move on to the next place where I know what happens. Or I work backwards from the end of the book. I almost always know where and how my books end. I know the beginning. I very know the middle. Which, of surprise to no one, is where I get stuck. But you know what? There's no magic in writing in a straight line. There's no reason not to skip and hop around inside a story if it's what breaks you free.
For me, working from the end reminds me of what these characters have at stake. I'm reminded of what matters to the arc of the story. Based on that, I can go back to the scene where I bogged down and I can ruthlessly pare it down to its bones - to the skeleton that supports the tissues and fibers of the story.
I suspect strongly that one of the major cures of writers block is giving up the notion that there are Right Answers when it comes to plotting and executing a story. There's only 'hey, this looks like an interesting direction, let's try it!'