So you're saying you held the same opinions at 25 as you have now?
You have not learned a thing ever since.
Blimey.
Sorry stephen as you can see there is no definite answer to this. Lots of differently equipped airplanes and to many willy wavers in here....
I do fly corperate and we usually switch the landing lights to pulse (they pulsate on and off) passing FL100 in the descent. We could use 3 different settings: landing lights: full power on the lights, recognition lights which is a reduced power setting, apparently leading to a longer bulb life and the pulse lights, which operate at the reduced setting. They (pulse lights) are switched on by the TCAS automatically should we come into a warning zone, meaning too close for comfort. (with a RA for the pros)
At night we use tailflood lights below 100. too.
Below 100 can mean a heck of a lot different distances to go to the threshold.
If one goes into London or my homebase in Germany, ATC will descend you way out, one regurlary sees 60-80nm below 100, if I fly into, e.g. Kryvih Rih in Ukraine it could be like 25 miles out, if I have my sporty day it might be as close as 20 nm...
On another Type I flew we had taxi/landing lights mounted to the gear and recognition lights on the wing tips. These were used below 100 and the landing lights switched on with landing clearance.