The first instruction is the hardest: leave the phone somewhere you cannot reach it without turning back. Twenty minutes is short enough to feel almost unserious, which is exactly why the walk works. There is no route to record and no pace to defend.
Begin more slowly than feels natural. Let your eyes travel to the middle distance instead of the ground directly in front of you. Notice three kinds of green, the temperature at the back of your hands, and the first sound that is not made by a person.
Let attention arrive before insight
The point is not to solve the morning. It is to stop feeding every open loop. When a thought asks to be organized, give it one breath and let the trail continue without an answer. Most thoughts are less urgent after five quiet minutes.
A useful walk does not carry you away from your life. It returns you to it with more room.
Turn around before you feel finished. The restraint matters. A practice survives when it fits inside an ordinary day, and twenty minutes is small enough to repeat before it becomes another ambitious plan.