Step 1: First Obtain a Toilet.
Step 2: Start by Breaking an Old Toilet.
Step 3: Knap the Pieces to Create A
Knapping ... Well... ever look at the cone of missing glass on the back side of were a bb has hit. This is what you work with. That is, when you wack the edge of ceramic or glass you will get the same angle on the back side as what the bb did. If the angle you hit the glass is off one way then you do not remove much materal if off the other then the cone of fracture enters the thickness of your materal and the flake brakes or the whole chunk brakes eather way it is not what you want. but if you hit it at the right angle then you get a nice flake. You can then flip your glass over and wack it on the other side and if right you get a sharp edge. This process is repeated over and over removing materal to shape and sharpen your tool. It takes hours and a 1/4 of a tollet to begain to get the hang of it. Be sure to wear gogals and gloves are not a bad idea.
Also see: http://primitiveways.com/knapping1.html