My favorite pots are antique crocks. 
These pots have a glaze that is salt fired. This glaze is created by throwing salt into a firing kiln. When the salt combusts it creates a glaze on the surface of everything in the kiln. Traditionally it was one of the easiest and cheapest ways to glaze pots. The pots would go into the kiln with nothing on them or possibly a layer of slip for decoration and come out of the kiln done after just one firing. It was an easy way to reduce the amount of loss due to excess handling of pots and make beautiful glazes that didn’t rely on the potter to make them. However salt firing produces sodium chloride, which is poisonous so it is illegal to do within most city limits and dangerous to the health of the potter.
I attempt to recreate this look and texture through a once-fired process. Modern technology has made the process of making ceramics much easier on potters. When the only option to fire pots was the use of gas, wood or oil the kilns were much larger, the process was very labours and at times more susceptible to total failure. With the development of computerized electric kilns potters gained precise control of the atmosphere in the kiln: they can bring the temperature up and down or hold it constant all in the same firing and with very little effort. I have used this technology combined with adapted traditional glaze recipes to make pots with extremely similar glazed surfaces.
In addition to looking cool it is also better for the environment because it uses less than half the amount of energy!
Each new glazes is developed from a series of samples or tests. I start with a conceptual idea of what I want the glaze to be like: color, texture, opacity.
The inspiration for the glaze colors comes from the nature around us. I start with a groups of tests based on what I know various chemicals to do in combination. After this initial round of tests with go through the results looking to ones that fit our desires and discovering some very intriguing surprises. 
We then test each new clay on a full size piece in the kiln with all the others to see how it will respond in a typical firing. If the glaze acts consistently we will then put it into production. Our glazes are full of depth and have lots of layers of color. Take a piece into the sun and look at the different crystals, flex and subtle shades you may not have noticed before.
As our company grows we hope to formulate our clay recipes as well to further our control of the end result.