Like with anything, I have good and bad days when it comes to writing, but the biggest success factor for me when encountering writer's block, is not to force it. There will be days when I knock out several thousand words and other days when I struggle to hit one hundred, and on days like the latter, I don't force myself to keep going. Not only do I find that I end up rewriting or just not really liking what I've written during these times, but it zaps the enjoyment out of writing as well. So when those grey clouds come floating in and I can't seem to push on, I simply don't. I take the day off and don't scorn myself for doing so. I write best when I want to write, not when I have to.