The Tips in detail

 "Using lights with fall-offs makes your scenes look more realistic."

Take a look at how real light behaves. It is not constant over any distance. Try holding up a lit torch (aka: flashlight) into the sky during the night. How far does the light's cone go? How does it behave comparing where it starts and where it ends? Do you notice the difference?

Light usually falls off (attenuates) at a rate of 1/(x*x) where "x" is the factor of distance. This is called "inverse square".

Using the "inverse" falloff will make the light to decay over the distance at a factor of 1/x where "x" is again the factor of distance.

The point at which decay begins depends on whether or not you use the attenuation settings. When Attenuation is not used, decay begins at the source of the light. When Attenuation is used, the decay begins at the Near End position.

Far Attenuation has no effect on the overall decay! Once the beginning point is established, the decay follows its formula to infinity, or until the light itself is cut off by the Far Attenuation settings. The distance between Near and Far attenuation does not scale, or otherwise affect the apparent ramp of decaying light.

The result is, that you have to do a lot of training and testing, until you get a feeling for setting up the lights "out of the wrist".

Due to the relevance of the distance for the light's intensity you will have to increase the multiplier or make the color brighter after you activated one of those falloffs. Remember that 50 is the maximum here. You can use a global multiplier via the environmental settings, but this affects all lights! Also refer to "Adding falloff-ranges to your lights speeds up rendering" for more information.

Using these falloffs will reveal if you made proper use of your measures and distances...