Choose a boundary
Pick a route short enough that getting somewhere is not the main event. A block, a courtyard, or the distance between two familiar crossings is plenty. Draw the start and finish first, leaving the middle open. This is a memory aid, not a survey, so north and scale are optional as long as the drawing makes sense to you.
Carry one pencil and use the same page for the whole walk. A limited toolset keeps the exercise from becoming a search for the right color. Stop in a safe place out of the way of other people before making a mark.
Collect three kinds of line
First draw an edge: the meeting of pavement and planting, a roofline, or a fence. Then add a movement: water leaving a downpipe, a branch in the wind, or a route people take around an obstacle. Finally add a change in texture. Brick beside rough render is more specific than a generic rectangle labeled building.
Use a few words for things the drawing cannot carry. A mechanical hum, the smell after rain, or an unexpectedly cool patch of air can anchor a page. Avoid recording identifying details about strangers; the exercise is about the place, not collecting other people.
Leave it imperfect
When the ten minutes are up, add one sentence about what surprised you. Do not redraw the whole page to make it attractive. The awkward proportions show what caught your attention and what you hurried past. That is useful information.
Repeat the same route at another time of day. Compare where you paused and which details disappeared. A small repeated exercise often teaches more about looking than an ambitious one-off drawing. Keep the two pages together so the differences remain visible.