Proportional symbol maps are used to represent point data that is attached to a specific geographic location or data aggregated to a point from an area. The map uses absolute scaling or range-grading methods, where symbols are sized proportionally to their values in the data. Two important design considerations for proportional symbol maps are avoiding homogeneous-looking maps and using the right method for your data. Symbols should be sized based on their value in the data, with larger symbols indicating higher values and smaller ones lower values. The map can include attributes such as color and drawing order to make it more visually appealing. Best practices for creating proportional symbol maps include researching cartographic research, experimenting with different design elements, and using CartoCSS to customize the appearance of the map.