Cameos require a few disparate skills and are a painstaking process to create.
First the vessel must be created with multiple layers of colored glass. This is done through a technique called a Swedish Overlay. I take a solid color bar and blow it into a bubble. Then for each additional color layer I create a bubble, press it to the first bubble and then invert the second bubble over the first so it coats it. I most often work with 2-3 layers, so I’ll often repeat this process again. The outer layers will tend to be opaque glass as I find that works best for the cameos themselves. Once the layers are in place I then blow and shape the vessel into whatever sort of cameo ‘blank’ I’m looking to work with. As with all blown glass the piece must be annealed and slowly cooled.
Second once the vessel is cooled I spend time with it and sketch out what I’d like to see on a given piece.
Finally I can now carve it! Often the direction of the design and art changes as I carve as I let the piece speak to me. I prefer very traditional technique of doing hand engraving using a special engraving tool with diamond bits; think of it as a fancy dentist drill. I find the hand engraving process allows a much greater range of results, textures, gradual fading and a more organic feel then you would get from a sandblasting technique.