Broad setting
Earth – present day, future, past, alternate past
Another natural body – planet, moon, asteroid, habitable, inhospitable, in a star system, drifting interstellar, inter-galactic
Artificial body – orbiting, drifting, mobile, enclosed habitat, large plate, spinning ring, ringworld around a star
Ship – military, merchant, passenger, leisure, exploration, generation ark
Exotic alternatives – parallel universe/world, alternate dimension
Natural body surface conditions
Percentage of land to surface water – arid, seas and oceans, sparse water cover, continents, large islands, little exposed surface, no solid surface
Geography – mountainous, volcanic, rough, smooth, cratered, weathered, firm, loose/unstable
Geology – rich or poor in metals, minerals, useful or harmful elements
Weather – placid, stormy, precipitation, drought, flooding, wind, cloud cover
Life – sparse, monoculture, varied, rich, dense, wild, tamed
Artificial body structure
Size – small, large, world-sized, even bigger
Geometry – clean geometrical shapes (spheres, cylinders, rings), symmetrical, haphazard, compact, spread out
Orbital characteristics
Day/night – short, long, tidally locked
Year – short, long
Axial tilt – zero through to ninety degrees
Moons, rings
Stable orbit and spin, perturbed by other bodies, unpredictable, single star, twin or multi-star system
Habitation
Cities, towns, villages – idyllic, industrial, vibrant, soulless, crowded, quiet, elegant, ugly, low-lying, high-rise
Other forms of habitation – floating, airborne, underground
Spread and density – sparse, spread out, dense, varied, uniform, confined to one/select area(s), completely built over
Nature of setting – urban, rural, farming, industrial, touristy, passenger terminals, military outposts, scientific observatories, ore processing factories, shipyards, trading posts
Look and feel – cramped, spacious, clean, grimy, tidy, cluttered, luxurious, spartan, imposing, homely, high tech, rustic
Environment – temperature, sounds, smells
Hazards to human habitation
Gravity – zero, low, high, extreme
Temperature – within tolerance (hot, cold) or extreme
Pressure – vacuum, low or high pressure
Volcanic or seismic activity
Radiation – solar, internal, artificial
Toxins, pathogens, caustic chemistry – air, water, soil
Predators, hostile inhabitants
Ian S. Bott, Writer and artist 