Allan Jacobs believes that good cities are made of good streets and that we are rapidly losing our talent for creating them. In this book, Looking at the City he says how just by looking we can tell a lot about a city. Careful observation is very important to achieve a good planning. Through observation one can get the idea about how old the building is, for whom it was build, who lives there now and how it has changed with the time.
Looking and just getting to its conclusion should not be the case. He says one should see and respond to it but only after analyzing and researching on it. You cannot say about the history of building by just looking at it, you have to interact with the locals and analyze it properly. A single building is just a single building till it has neighbouring buildings and activities added to it. All the details together make a pattern of information which helps to relate and imagine the scenario.
Observation is the key element to any design. It helps a layman as well as architects and planners to understand the city. Concluding this, I would say that people should start observing and start deriving results from it.