Quote from awesomlyawesome
Mainly caving. However, I don't usually mine all the diamonds i find when I find them. I'll write down the coordinates, and then get a pick with fortune to get even MOAR diamonds.
Once you have a fortune pick, you can keep repairing it as it wears out. A Fortune III + Unbreaking III pickaxe that is constantly repaired can super-multiply your diamonds for just about forever.