The inverse law is irrelevant in incidental light readings (after all, if the light comes from the sun -92 million miles- does it matter which side of the Grand Canyon your'e standing on in relation to your subject?)

However, what does matter is that both your subject and the meter are in the same light (not subject in the shade, you in the sun etc).

Point the dome on the meter towards the camera (away from subject) along a line parallel to that between the camera and subject.

Can't be any simpler!