Use the in-game chat command `/locate structure minecraft:trail_ruins`
Search warm ocean biomes for suspicious gravel and decorated pots
Look for trail ruins partially buried underground in taiga, snowy taiga, old growth taiga, and jungle edge areas
Explore with a brush to uncover suspicious blocks
Check chunk borders and riverbanks near those biomes
Use Creative mode or spectator mode to scan terrain faster
Use external seed maps or structure finders for your world seed
Enable coordinates to mark and revisit promising locations
Search at night with night vision for easier spotting of exposed structure blocks
Dig carefully around gravel patches in the target biomes