Find at least 2 adult villagers
Make sure both villagers are willing to breed
Place enough beds for the villagers and the baby villager
Give the villagers enough food
Use bread, carrots, potatoes, or beetroot
Throw food to the villagers until they pick it up
Keep the villagers close together
Make sure the area is safe from mobs
Wait for hearts to appear
Wait for a baby villager to spawn
Add more beds and food to breed more villagers