Digging

Digging requires a Shovel. Activate shovel ---> Right-click a tile (any but rock) and select Dig. This will lower the ground and put 1x of the tile compound in your inventory. The ground is lowered at the closest corner to where you are standing, rather than where you click.

So if you want to lower a tile stand in the corner of the tile activate your shovel, right click>Dig this will lower the corner you are standing on. To lower the whole tile, you must stand in each of the four coners in turn and dig. This is the same for raising a tile, just drop dirt instead of dig.

When You think you have a tile nearly flat you can find out if it is perfectly flat by right clicking>flatten.. If the timer that tells you how long left there is to perform the task starts at 0:09 seconds then it is flat. If it doesn't start at this time right click again and select stop. Then dig where u need to flatten the tile.

A better way to check the flatness of an edge of the tile is to press 'c' key, then look at one tile and if the line is straight, then you are sure it is flat.

Digging for rock:

If you want to dig for a rock tile you must be aware that you could dig alot of dirt. To start you must dig a reasonabe distance above water, keep digging in one corner till you "hit rock" or you dont have enough skill to dig deeper. Once you hit rock in one corner you must then dig till you hit rock in the other corners of the tile. Doing so you will un-cover the rock.