Choice of Fog /Accessory Lights

[pekingduck]

I think driving lights work best when mounted as high as possible, pointing down ahead. Lights that are eye-level reflect the most light back at your eyes, as seen on most P-D bikes. I've ridden off road with super-brite helmet-mounted LED lights, and they are the just phenomenal. (Just remember not to look at anyone directly.)
Long-range, low-mounted driving lights are not very effective (except in blinding others), since they are aimed upward.
On cars at least, I've found foglights to be ineffective, even if they are mounted low, with yellow lenses, unless you can turn your headlights off. The headlights will blind you, but at least others know there's someone there. If I get caught in fog, I swivel the headlight down and just go slow.