It occurs to me that in all our discussions of the merits of different builds, outputs, interfaces, etc., we don't often discuss general handling issues that could have a big impact on how effective our flashlights use is.
Sure, there are plenty of threads on the topic of flashlight/weapon combinations (which makes sense, given most of us only have two hands - well, plus one mouth usually ). But what about more general uses where you have found a certain approach that works remarkably well? I'll start with two examples that occur to me:
Eye shine for spotting critters:
I was taught this one by a field naturalist. With the light on low, hold the light at the level of your eyes, and track the center of the beam as you scan a night scene. Because of the angle, you will catch critters by the "eye shine" reflections off the tapetum lucidum at the back of their retinas (common in many vertebrates). Of course, this works when animals happen to be looking at you.
This trick is remarkably effective, with relatively low powered lights (although throwier ones work best). Depending on what type of animal you are looking for, adjust the height of the beam center appropriately (i.e. tree branch level, gound level, bush, etc.). Apparently you can even distinguish some species by the color of the eye shine, but that's complicated by the angle and the source characteristics of the light used.
You will be amazed at what you find. I have surveyed a range of rainforest trees under high power with a traditional underhand grip and seen nothing (a lot of animals blend it petty well). But after switching to a lower output and scanning this way for eye shine, I picked up all sorts of things. Needless to say, a big clumsy human walking around shining a light attracts all sorts of attention - they will be looking at you, alright.
Oh, and if you want to gross out friends and family, try this at night on your own back lawn (if you live in a suburban area). Detect tons of little diamond-like sparkles in the grass? Move in closer on one pair to find out what they are ... bet you never knew how many spiders there were in a typical subdevelopment.
Shadows are your friends when dropping things on the floor:
We've all had the experience of dropping small objects on a floor where they blend in too well (small screws, pills, and granola bits come immediately to mind ). Want to find them a lot easier? Scan the surface with your flashlight parallel to the floor (i.e. horizontal, as if it were lying down on its side).
As long as the floor surface is fairly flat, you should spot the runaway object pretty quickly by the long shadow it leaves. I've got a heavily patterned area rug under my desk right now, and I know from experience how hard it is to spot things otherwise. But a quick sweep with my hand low to the ground picks up even the smallest item this way.
Those are my two best tips. Any others you would like to share?