When designing fictional coasts the general biome and local terrain features are critical components. A tropical island will be drastically different than a fjord-filled landscape. Consider what the general location is like and how the coastline reflects that. Hilly or mountainous regions may be more likely to feature coastal cliffs and sea stacks, while tropical islands may be home to lagoons, sandy beaches, coral reefs, and sandbars. Sea caves are a common element for worldbuilders to include when designing their coasts.

The coastal waters surrounding a landmass can also be an opportunity to explore aquatic locations and elements. Treacherous waters (often located beneath coastal cliffs or surrounding sea stacks or jagged rocks) are often used to create danger in narratives. Worldbuilders may also wish to consider coral reefs, kelp forests, and tidal flats.

Fictional coasts are often dotted with shipwrecks, lighthouses, partially submerged ruins, small fishing towns, and seaside taverns. These locations can be used to deepen a world’s fictional history and culture or as locations of quests or mysteries in narrative and game worlds.