This post is for Ren's use. http://hydra-media.cursecdn.com/minecraft.gamepedia.com/thumb/d/d0/Diamond_D_28x.jpg/500px-Diamond_D_28x.jpg I mine Y layers 8-9 as branches, which leaves 7-10 visible, then 11-12 atop that, leaving 10-13 visible. Trying to get layers 5-6 seems worth it, but it's not. Technically you can leave 3 lines of blocks between branches, since there's actually very little chance that diamond ore spawns are going to be 1 block wide. But both me and nob prefer to cover that inner line so we skip 2 blocks over between branches. That's probably the best way to mine for diamonds in particular. You'll get everything else doing this, coal, iron, gold, redstone, lapus lazuli.