For the better part of two decades I've carried a flashlight everyday in my pocket. To the point that I can honestly say that if one where to count the hours in a race per se the flashlight would very well trump both the pistol and knife in my carrying. If only for the sake of being separated from two of those articles due to legal constraints (court rooms and airplanes).
I've walked through burned out buildings, crime scenes, tied flies to a line, read a book, cleared more than a few buildings and done all those "neat" tactical moves like they do on the t.v. , all with a flashlight between my fingers or teeth. Yet it was a power outage a few years back that taught me something really useful to do with a light.
Point it up.
If you're in the dark, inside, and not doing one of those uber cool room clears (you should practice that by the way) but, just trying to maneuver through the dark point your light straight up. This working especially well on ceilings 8-12 ft high.
What does it do that pointing it out in front of me doesn't do?
Well for starters it places your feet inside a ring of light as opposed to a shroud of darkness.
The secondary advantage is given the high lumen output on so many lights one can end up blinding others if you turn without thinking, putting your light on them. When pointed in the traditional method you get light only where the cone goes and how the beam is focused. Bounce it off the ceiling and you get the same effect of a floor lamp....wide spread illumination.
Lastly, it does one other thing. Brings about a calm to other people with you who don't have a light. The guy with the light gets to calm his heighten concerns first because the flashlight goes wherever thought's tell it to, anyone else by default is forced to observe whatever the torch bearer observes leaving them literally in the dark. With the light pointed up and three hundred and sixty degrees of illumination provided everyone else can look where they so choose.
It may not sound like much, but moving through some dark place with a child clinging to your pant leg crippled with a fear of the dark can be at most a real problem and at the least a frustration. Thus causing your freedom of movement to be semi-impeded.
"Tactical" lights as we call them now days are phenomenal for blinding an aggressor but, day in and day out you are going to be called to use that light in everyday occurrences.
The better the illumination the safer and calmer anyone (and everyone) is going to be in an already trying and tense situation.