Create a drawing of the object that you wish to carve in marble. Draw the object from as many angles as possible, marking the desired size of the sculpture in the drawing.
Obtain a piece of marble as close to the size and shape of your proposed sculpture as possible in order to reduce the amount of carving necessary to create your sculpture.
Reproduce your drawings onto the actual stone using pencil or crayon to serve as a rough guide to your carving.
Set up the stone for carving by placing it onto several filled sandbags for stabilization, all on a strong stable work surface. Make sure your work area is well-lit from all angles and well-ventilated to reduce the inhalation of marble dust.
Put on a pair of safety goggles, hearing protectors and a dust mask. Rough out the sculpture's shape by removing most of the stone from around the drawn guides with a heavy chisel and hammer. Place the chisel onto the stone where you need to remove a chunk, then hit the head with a hammer to break away a piece of the stone along the angle of the chisel. Work with small sections of stone, chipping away at the piece bit by bit until the rough shape of your sculpture begins to emerge. Stop the roughing out when you're within about a 1/2-inch of your roughed shape.
Switch to a point chisel for a bit more control in the stone removal. Hold the chisel at an angle of about 45-degrees to the stone where you need to remove a section, and then hit the chisel head with the hammer to take out a straight line of material along the angle. Use the point chisel until you've created your rough stone shape.
Change to a claw chisel to begin to develop detail in the stone and to smooth away the lines created with the point chisel. Switch to a toothed chisel to further refine the sculpture shape and remove those lines left by the claw chisel, smoothing the surface of the marble even more. Go over the lines left by the claw chisel with a flat chisel to smooth away the last of the rough chisel lines.
Use a rasp to place the last of the fine details into your sculpture and remove any remaining chisel marks left from the flat chisel.
Smooth the rasp marks with a file. Grind the file across the surface of the marble along the mark, removing the buildup of marble and leaving behind a smoother marble surface. Be careful not to file down any fine detail in the process.
Sand the sculpture smooth using progressively finer grades of wet/dry sandpaper. Begin with 100 grit and work your way up in grits until the sculpture is as smooth as you wish. Each successive pass with a new grade will remove some of the roughness of the sculpture, smoothing the surface of the statue just a bit more than the previous grit. Keep the sandpaper saturated with clean water as you work to keep the marble dust down by submerging the sandpaper into a bucket of water whenever it begins to dry. Wipe the surface of the marble free of dust after each sandpaper pass with a clean dry cloth.
Polish the stone after carving, if desired, to create a gloss finish or display as is.