Many websites and apps allow you to create a map and add pins to mark specific locations. Some popular options include Google Maps, Bing Maps, and MapQuest. Simply search for the location you want to pin and click on the map to add the pin.

On your computer, open Google Maps. Right-click the place or area on the map. This will open a pop-up window. You can find your latitude and longitude in decimal format at the top.

Start with just a rough outline using straight lines to sketch out the landmasses. When you've gotten the outline just the way you want it, go over it again to create a more detailed outline (typically a bit wavy) depicting coasts and borders.

Maps are created with one layer, but you can have up to 10. On your computer, sign in to My Maps. Open or create a map. You'll see your layers in the box on the left.