First the template from the bastion
What is needed is the netherite upgrade template, not the armor finishing. Look for bastion chests; in the treasure room there is a guaranteed pattern drop, in other chests the result is random. Gold armor doesn't calm piglin brutes. Reference: Java 1.20: forging templates.
To copy, place the template on top in the center, net in the center, fill the remaining 7 cells with diamonds. The result will be 2 template taking into account the original one: the net increase is equal to one.
One ingot per item
Smelt 4 ancient debris into 4 netherite scrap. Mix 4 scrap and 4 gold ingot - you get one netherite ingot, the location does not matter.
If you find one template and want to improve four things while saving another template, you need to make 4 copies: 28 diamonds and 4 non-zero. For four bars you will need 16 fragments and 16 gold bars. The price of diamond blanks is not included here.
The manual route for mining the original debris is described here: Finding and mining ancient debris in the Nether.
Slot order in the smithing table
A blacksmith's table is made from 2 iron ingots over a square of 2×2 boards. In its interface: template on the left, diamond item in the middle, netherite ingot on the right. Read the result hint before receiving.
The name and enchantments are retained. A netherite item does not burn up from fire and lava like a normal item, but is still lost in the void and can disappear for other reasons. The upgrade does not replace the backup kit.
If you want a different mining result, compare the two pickaxes: Fortune or Silk Touch: which pickaxe should you make first?.
