Here are some approaches you can use to create a fictional continent that feels realistic, has regions that naturally fit together, and offers tons of adventuring opportunities for your story/game characters. (Note: we're using principles for 'alternative earth' settings like those common in fantasy literature.)
THINK ABOUT PLATE TECTONICS As you draw an invented continent, keep in mind that most high mountain ranges and active volcanic zones are likely to be found near its edge, in the parts where other tectonic plates are slowly diving beneath it. Central areas of continents are commonly plains, possibly with low mountains. Coastal areas far from plate edges have similarly low terrain.
THINK ABOUT GLOBAL CLIMATE ZONES The planet is circled by latitudinal climate belts, each about 1500 miles wide. Think about the placement of your continent on the global diagram below. What climate zones are found right next to each other? Is your continent large enough to cross through several belts? What, if any, transitional climate/vegetation regions are likely to exist between the landscape settings you had originally planned to include on your continent, and what new adventures might happen in those places? What are the main wind directions?
THINK ABOUT THE CONNECTIONS BETWEEN REGIONS Neighboring regions affect each other. Orographic effects of mountains can create forests on their heights and windward sides, and create deserts just downwind, even in temperate or tropical climate belts. Most large rivers head in mountains, passing through plains and coasts on their journeys to the sea. Volcanic activity can build new mountains and offshore island chains. As mountains erode, they shed sediment to nearby areas, leveling them out into plains.
THINK ABOUT LANDSCAPE VARIETY IN REGIONS One desert area can be quite different from another in its terrain, vegetation, and peculiar landmarks. Humid lowlands can be forests, prairies, hills, or swamps. This Ground for Inspiration website is one source you can use to experience different specific settings in mountains, on coasts and other regions - more than 40 landscape scenes in all! Just click on these menu links to explore: Environments & Elevation Levels .