Scale cues make things epic
The model doesn't know your dragon is enormous unless the composition proves it. Add scale anchors: 'tiny figures on the battlements below', 'birds circling its shoulder', 'the tower reaching only to its knee'. Atmospheric perspective sells distance — 'layers of mist between the foreground ruins and the mountain city'. And low camera angles ('worm's-eye view looking up') make anything towering feel mythological.
One scale anchor per image is enough. Prompt it explicitly, every time.
Light is your magic system
Fantasy lighting works when magical sources behave physically: 'the sword's blue glow reflecting off wet cobblestones', 'lantern light catching the underside of the dragon's wings'. Pick one dominant light source and one accent — dueling light sources flatten drama. Time of day is a free mood dial: dawn mist for hope, sickly green dusk for corruption, hard moonlight for dread.
Campaigns, novels, and worldbuilding bibles
Tabletop GMs generate scene reveals and NPC portraits per session; fantasy authors build visual bibles of their world for consistency (and eventually, marketing); worldbuilders illustrate wiki entries for every region and faction. Keep a fixed 'world style block' — palette, architecture era, atmosphere — so a hundred images across months still read as one canon.