Yesterday on a whim I decided to give Dark Field or Bright Field Lighting a try, so I started setting up a shot after school in my classroom. I had brought this sugar shaker (sans lid) in from home a while back, because I liked the shape and thought it'd be an interesting subject. I used a couple different setup photos from the internet as my guide. I placed the jar on a very dirty piece of glass atop a piece of black foam core. I figured I'd set up the shot and if it was looking good I'd take the time to clean off the glass. I placed a strobe light below the table, directed it at a white piece of paper on the wall, and attached my fancy snoot (made from a cardboard mailing tube) to direct the light and prevent spillage. Finally, I placed two more pieces of black foam core on either side of the jar. In the end I don't know if it's a Dark Field or Bright Field success--I'm still a bit confused on the topic and want to give it another go after more reading. But, I liked the result anyway, and it got me shooting, so I'm happy. Oh, and if you look at my setup shot below you'll see that I never ended up having to clean the glass... :)
Editing details: Shot in RAW, so first editing was done in CameraRAW. In Photoshop I duplicated the background layer, converted that to black & white, and set it to Soft Light. I also added a magenta layer set to overlay and at a very low opacity.