Sometimes your mind is blank, and no matter how hard you think, you can't find anything in it worth putting on paper. That's when you have to make what I call a “switch off”. Instead of trying to switch your mind on, you switch it off.
Naturally, you can't switch it off completely. If you did, your body would collapse and start emptying its urine and faeces all over the floor, like when a person dies, and you don't want that (I hope not).
When I'm talking about a “switch off”, I'm referring to allowing your hand to write whatever it wants, even if it doesn't make sense.
It's the equivalent of drawing doodles on a piece of paper while being on the phone with someone, or dancing like nobody is watching. Only here, it's with letters and words.