Keep the same face across renders

Identity holds through a look sheet and references; wardrobe holds through words. What to do when a character drifts.

Give the character an accepted look sheet from consistent photos — same hair length, same art style. A sheet made from a short-haired photo and a long-haired one makes the engine pick one per render.
Describe the wardrobe in the prompt every time. Identity (face, build, skin tone) holds more strongly than clothing, which follows the words.
Pick an engine that reads reference pictures: the model page and the picker say how many each one takes. Sora 2 Pro, Runway Gen-4.5, Grok Imagine, Veo 3.1 Lite and Hailuo 3 Max work from text alone.
For near-identical variations, use a seed on an engine that honours one, and change a single thing between renders.