You fly along checking the right of way. Backhoes, bull dozers, etc. Any activity or equipment that could jeopardize the integrity of the line.

I've got a buddy that has been doing this for years. He's making close to $50K flying and a/c'ed 182 with AP and GPS. He flies the same routes every two weeks M-F. All VFR. His company has an observer that watches the line. He just flies.