Nowadays when I get stuck on a writing project, I'm learning to move my attention away from the problem I'm trying to solve. I close my eyes and pay attention to what's happening in my body as a result of being stuck. Where's the tension located? I take time to feel it. Is there sadness beneath the hard surface? A feeling of freedom somewhere under the skin? I simply watch; I don't feel obligated to obtain a result from the momentary quiet, which is a relief.
It's kind of weird how we run around in our bodies, but we live as if reality takes place in the mind. Actually, the body is a kind of subtext--things that we don't want to consciously acknowledge are written there.
And sitting quietly can free up access to corners of your consciousness where you already know how to solve a problem. When I'm really tense, sitting quietly reminds me that there's more to me than the reactive, pissy me.
Again and again, I have to remind myself to do this. Old habits die hard! The body can be a source of wisdom, but it's too easy to treat it like a household appliance, used so often it's almost forgotten.