There are a series of questions that go through the process of creating a realistic world step-by-step.
This is a series of questions that tries to break down the process of creating a world from initial creation of the landmass through to erosion, weather patterns, biomes and every other related topics. Please restrict answers to this specific topic rather than branching on into other areas as the other stages will be covered by further questions.
A list of all the questions in the series can be found below, so that a link to this meta post should be enough for future questions.