There are many elements that are taken into consideration to make a mural. For example, in the scale that will be used, by this I mean the proportion of the size of the drawing with the size of the person who sees it from a distance. Also, how the it is integrated with its surroundings and with the rest of the facades that are around it. The colors and the design say a lot about what the author of the mural wants to express with it.
Do you have a favorite mural in your city?