Here is the final shot and how it was done for photo class this week. Note, the setup shot was taken with my iphone so its not DSLR quality but you get the idea of how e setup the shots.
As you can see here, we have a couple sawhorses setup with a piece of glass between them, then a piece of acetate is draped over a C-Stand and over the glass. The subject is placed on the glass and its lit from below with a hot light or a strobe.
That is the basic setup, to which we added a strobe behind the C-Stand to light the background. Getting the light positioned directly behind the subject and directly in line with the camera is critical for good reflections and an evenly lit background. The double layer of acetate did a good job of diffusing the light coming from the strobe, but in the final shot we added a softbox to spread the light out even more.
Here is my final shot. My original vision for this shot was to have a couple shot glasses next to each other and a bottle of Jack Daniels ready to be opened. The problems arose when you put transparent objects in the scene. The light that is going through the glass to the camera is transmitted and any solid subjects you put in the scene (like my bottle of Jack Daniels) offset that if they have labels or other solid areas that reflect light to the camera. It opens up all sorts of difficulty because your lighting setup changes drastically. Anyway after fightign with the Jack Daniels bottle for an hour I decided to take it out of the scene and just put the shot glasses in there. This one was one of the first done with that simpliied method. The biggest challenge was getting the hoizon line to match up with the elipse of the lower shotglass. I did forget to mention that a small yellow gel was placed over the lower strobe.
Pretty neat illusion huh?