If you know the word you are looking to highlight (and the title helps to confirm that), you can guess that its letters might be evenly distributed throughout the grid (think quadrants). None of the examples is a straight line, but taken together they form letters with at least one axis of symmetry. Your H sounds right.
My only issue with the puzzle is that I believe there need to be 8 examples (51 letters) highlighted to reveal the word. I am taking that as a misprint, but it would be handy if anyone would confirm