Mine quartz in the Nether
Build a mob farm
Kill mobs at a spawner
Smelt items in furnaces
Breed animals
Trade with villagers
Fish for XP
Mine ancient debris, diamonds, redstone, coal, and lapis
Use an Enderman farm
Kill the Ender Dragon
Use an XP bank from stored furnace smelting
Cure and trade with zombie villagers
Raid a pillager outpost or raid farm
Use a gold farm
Use a guardian farm
Use an automatic cactus or kelp smelter setup