So every excuse I've ever had about why I'm not writing has been met, down to a new (refurbed but new to me) laptop. I eagerly open up a manuscript I'd started and proceeded to stare.
I forced myself to write. It sucked. I backspaced. I wrote some more. It blew chunks. I backspaced again. And again. Then I made myself stop thinking and simply DO it, knowing I could remove it later if I needed to (which, without a doubt, I would), and got to the end of the scene.
And then I realized that since I wrote that little beginning with just an idea of the story, I knew next to nothing about my character. Well, you can't write without knowing the character, so I started on a character worksheet to try to get into her head. My own head is confusing enough. We can only imagine how hard it is to get into a character's head that comes from my head. Kind of as confusing as that last sentence, but I think you know what I mean.
So tonight I'm whipping out craft books on characterization. This is just like anything else: You have to retrain your mind to do it. Flex those muscles and get them limber enough to work with ease.
And try not to get a brain cramp in the process.