Examples for inspiration can be found here.
Safety first!
Eye protection because small bits fly everywhere!
Work wet to avoid breathing stone dust or wear a breathing mask. Once it is in your lungs it is never coming out.
Spike for removing lots of material at once.
Chisel to start shaping the surface you want.
Rasp to remove and smooth the material.
File to smooth and shape the surface.
Diamond pads to smooth the surface.
Wet sandpaper to polish the surface.
Saw for cutting of large chuncks
Multitool diamond ends for detail work
Spike
Chisel
Rasp
File
Diamond pad
Wet sandpaper
Saw
Multitool ends
You need to some how figure out how to get a 3 dimensional shape out of a block of stone by removing the stone you do not want. The question is how do you know what stone you do not want? Use a model.
Model types
Draw your object from multiple perspectives
Find pictures of an object from multiple perspectives
Make a model out of clay or blue tack
Print out a 3D model to follow
The model is for inspiration, not to be merly copied. Usually the end result will only resemble the model, not be an exact copy.