Quick Answer

A good seed is not only a pretty spawn. For a long survival world, useful structures and resources should be reasonably reachable: villages, Nether access, strongholds, ancient cities, trial chambers, wood types, and rare biomes are all worth recording.

Recording Template

TypeRecord ThisWhy It Matters
SpawnCoordinates, food, wood typeOpening route
VillageCoordinates, job blocks, smith housesVillager economy
TerrainMountains, ocean, desert, swampBase and resources
StructuresStronghold, ancient city, trial chamberMidgame and endgame goals
NetherBastion, fortress, dangerous terrainBlaze rods and materials

Exploration Method

Start by mapping resources within about 1000 blocks of spawn, then expand through main roads, Nether coordinates, and End routing. Bring bed, boat, food, blocks, and spare tools on long trips so exploration does not become a one-way journey.