Find a dark area above ground or build high in the sky
Gather building blocks, slabs, water buckets, hoppers, chests, trapdoors, and a killing method
Build a large spawning platform or several stacked platforms
Make the platforms completely dark
Add water channels to push mobs toward a central drop
Place trapdoors or signs to control water flow and mob movement
Create a 2-block-high spawning space if needed
Build a drop shaft for mobs to fall into
Make the drop tall enough to leave mobs low on health
Add a killing chamber at the bottom
Place hoppers under the kill spot
Connect hoppers to chests for loot collection
AFK near the grinder so mobs spawn and move into it
Spawn-proof nearby caves, land, or structures
Use slabs, buttons, or torches to prevent unwanted spawns around the grinder
Test the grinder and adjust water, lighting, and drop height if needed