Enter the Nether through a portal
Move in a straight line for a long distance
Search along the north-south axis first
Increase render distance if possible
Look for dark red brick structures
Search above lava oceans and open areas
Travel on bridges or high platforms for visibility
Use coordinates to track where you have searched
Explore multiple Nether biomes
Listen for wither skeletons and blaze sounds
Check near lava seas and large open spaces
Use a horse, strider, or boat where appropriate
Bring blocks to bridge across gaps
Mark explored areas to avoid backtracking
Keep exploring until fortress corridors or towers appear