Minecraft wiki entry for Mining, associated text: Creating a Branch Mine is simple. First, dig deep underground until 0-16 blocks above the bottom level. To keep track of this, press F3‌[JE only] or type /gamerule showcoordinates true‌[BE only], and the Y-coordinate tells the vertical level the player character is currently at (It is best to mine at level 11 because it is easier to deal with lava lakes on that height). Upon reaching the desired level, begin to dig at least 20 blocks into a wall to create a shaft. Come out of the shaft, move at least 3 blocks to the left or right, and do the same again, digging 20 blocks into the wall. Each shaft made will almost always contain a resource block ranging from coal, iron, redstone to even gold and diamond.