One of the most important things that you can do before carving your stone is to properly plan out the carving. There are several ways that you can do this. Some artists create concept sketches of what the carving will look like with a series of drawings on paper. These drawings can later be used as references during the carving. If you do this you should also consider drawing detailed illustrations of key points of focus on the carving. For instance, if you are carving a figure, make sure to have a detailed drawing of the head.
You can also draw an outline of the sculpture on your block of stone. This will give you an idea of where to start carving and chipping away. You won't be able to draw a highly detailed illustration on the stone, but a basic outline can give you enough of a starting point so that you can get to work.
According to TheSculptorStudio.com, you can begin to shape your sculpture and remove any excess stone with a pitching tool. You can begin to remove the excess stone with this large tool by striking it against the stone at an angle. This tool should not be used for detail work and is best for getting the sculpture into a very basic shape that resembles your final product.
You can use a smaller tool, called a point chisel, to flesh out more of the form of your sculpture. It is best to go slow when removing this excess stone, as it cannot be added back later.
You can use a chisel to begin to shape and give detail to your sculpture after it is in its basic form. At this stage, you don't want to accidentally remove too much stone, so holding the chisel at a 45 degree angle can help ensure that your strikes will only flake off stone and slowly give more shape to the sculpture.
At this stage, you can also use rasps of varying sizes to hone down the shape of the sculpture. Rasps are easier to use than the other tools because you are literally scraping off the stone where you no longer need it. You can switch to smaller and smaller rasps to further refine small details.
After you have carved the stone to your liking you can polish the sculpture by sanding the stone with wet sandpaper. This will give your sculpture a smooth look that also shows off the veins of minerals within the rock itself.