When taking a visibility observation, what is the best practice?

Taking visibility observations from as many locations as practicable is a best practice because it provides a comprehensive picture of the visibility conditions across an area. Visibility can vary significantly due to factors such as terrain, obstacles, and weather phenomena (like fog, precipitation, or smoke), so relying on a single point may not represent the overall visibility accurately. By assessing multiple locations, observers can capture variations in visibility that might be caused by localized conditions, ensuring a more reliable and informative observation. This approach aligns with aviation safety protocols, which emphasize the importance of accurate and thorough weather reporting for navigation and operational decision-making.