Walking, showering, sleeping, and riding a bike are great ways to debug code.
It's very cool to go to sleep and wake up knowing what the solution to the problem is.
The key for incubation for me is to make sure my brain can churn without distractions (that means no listening to podcasts, music, etc while performing said action).
Walking with no music + not using your phone. Leaves you plenty of space to think.
Truth. Nothing is a greater spurn to creativity (cyclic mental exertion) than time away focusing on cyclic bodily exertion.
Yup, that's the https://en.wikipedia.org/wiki/Default_mode_network
It's the daydreaming/mind-wandering state that occurs when you're not focused on an external task. With all the stimuli of the modern world, I feel like we're being starved of crucial DMN time if we don't engineer conditions like the ones you describe.