I learned early on that one of the secrets to campus leadership was the simplest thing of all: speak to people coming down the sidewalk before they speak to you. I did that in college. I did it when I carried my papers. I would always look ahead and speak to the person coming toward me. If I knew them, I would call them by name, but even if I didn't I would still speak to them. Before long, I probably knew more students than anybody in the university, and they recognized me and considered me their friend.
Your purpose is to make your audience see what you saw, hear what you heard, feel what you felt. Relevant detail, couched in concrete, colorful language, is the best way to recreate the incident as it happened and to picture it for the audience.