I'm just not sure how the mining mechanics work exactly. Currently I just have a straight tunnel into the mountain and want to make a big empty room (like a giant cube) below the level of my tunnel. Do I mine out the top of the cube then stand on top and mine down?
Part of the problem I have is I think to myself that the world is made up of blocks (like in minecraft or something) when that is not the case.
Also how did you make those big pillars? Just by not mining that area out?