Visit toy and hobby stores and examine miniature models of buildings, landscaping, people, roadways, pedestrian paths, railroad tracks and other objects you can use to model a complete city.
Sketch a map that defines the boundary of your city and its scale. Divide the map into equal sized square grids. Draw in natural landscape features such as rivers, creeks, beaches, and mountains.
Lay down a checkerboard cloth on a solid level surface such as a table top. Place models of the natural landscape on the cloth. Use the grid on the checkerboard cloth and the grid on the sketched map to position and place hills, creeks, rivers and beach models on the table cloth.
Arrange the man made models you plan to use in your city game into groups. Group houses, buildings, telephone and utility poles, underground pipes, roadway and path pieces in separate sections.
Write down rules for your game on index cards. Include rules that define and limit the placement of models in your city and how many specific types of models can be placed during a single game turn. Create rules that would mimic city zoning laws that limit the development of specific types of buildings, businesses, homes, roadways and bike paths in specific areas of the cities.
Test the game. Have one player select a card from the top of the stack of index cards and then place the city game model pieces according to the rules on the card. Have the next player pick a card and place city game models according to the rules on that card. Continue in this fashion and observe how the rules shape the development of the city.