A Walk, Alone
At the beginning of WG Sebald's The Rings of Saturn, the protagonist sets off on a solitary walk in the county of Suffolk. He walks carefree for hours each day, but the death and devastation he contemplates while abroad catches up with him and lands him, a year later, in a prisonlike hospital room, "in a state of almost total immobility."
In Frankenstein, Victor Frankenstein goes off on a walk in the rain in the Alps, hoping to forget his cares. He goes alone, lest the presence of another destroy the grandeur of the mountains, and so it is that alone, he meets his creature, the monster, and is forced to hear his story.
What is it about solitary walks in literature that makes things happen? Perhaps it's the fact that so many writers do their thinking on their feet.
Take a walk, alone, and observe your surroundings closely while thinking about your story. Ask yourself what you saw, remember what you thought about. Maybe you'll figure out what happens next, or get a new insight about a character that has needed depth, or perfect a single line of prose. Maybe you'll decide to send your character on a walk of their own. Write whatever you gain on your walk into your narrative.