If you're standing in front of a blank slate, a blank page, "the white bull" as Hemingway called it, and you're stuck, go do something else.
I'm learning to let myself do that. To give myself permission to let up on the gas and steer elsewhere.
Get up for an hour, for the afternoon, whatever. I just sat down at my desk and was getting nowhere. So I made a coconut london fog and went and scrubbed the bathroom down. Yeah, that's random, it's usually a walk or taking a few photos or a phone call.
But your mind can go outside the building of your writers block or problem or stress and have a smoke while you stare down the barrel of a toilet and commit your work to a completely different endeavour.
I find it helps.
And I guess that's all I wanted to say.
Get something done today, work at something today, even if it's not the thing you expected.