Daguerrotype Simulation

This gives an old-photograph look even without writing anything directly in the prompt. Words like "grainy", "blemished", or "weathered" lend some extra oomph and unpredictability.

Strength of 0.8-1.4 seem to work best so far. It all depends on what you're after.

Use a photography-style checkpoint to get away from fake-looking, digital painting results.