Use a crafting table to combine two damaged items of the same type
Use a grindstone to repair by combining two of the same damaged items, removing enchantments
Use an anvil to combine a damaged item with another of the same type or with the matching repair material
Use an anvil to combine an item with an enchanted book while repairing it
Use the Mending enchantment to repair gear with experience orbs
Use the item’s correct repair material for anvil repairs
Keep enough experience levels for anvil use
Replace equipment if repair costs become too high on an anvil