Lots of good tips, particularly outdoor/overcast.
Coin finish with engraving gave me probs with specular reflections, and Ken Hurst solved them fast: Mix copier toner into a Rig-rag, then wipe on/into engraving.
If you start with absolutely flat lighting (equal wherever you point your incident meter), you can then add highlights and shadows as desired. A 1.5 or 2:1 ratio is a good place to start (higher for greater drama or impact.) Tinker's look like around 3:1, perhaps higher in the bottom one.
You can create flat, reproducible lighting indoors the way Oscar did: Four equal photofloods or flash units at the top corners of a cube, with the subject at the cube's geometric center. Diffusers are helpful. Individual light's distances can be varied from selected corners to create departures from perfectly flat lighting. A PVC pipe cube frame works well.
Includint a neutral grey card (and it doesn't have to be a very big piece) for color balance is a great suggestion. Metering the exposure off a full sized card is most pro's starting point.
