Make it as simple as possible for the referee to evaluate exactly what you’ve done to address his/her concern. That means, don’t just say “I addressed your concern in the second paragraph on page 54.” First, remind the referee of his/her exact concern; most referees don’t recall exactly what they were concerned about, and they are busy and don’t want to go to the trouble of reminding themselves about your paper, so the easier you make it for the referee to recall why they were concerned, the better off you will be. Second, restate the concern as you understand it. Third, explain the approach you have taken to resolve his/her concern. Fourth, put the same thing in the reply as you put in the paper; don’t even make the referee manually go to page 54 and read the second paragraph (or whatever). S/he will probably go there and read it in context anyway, but you want the referee to already be 90% convinced that you’ve addressed his/her concern. These four steps are always the best way to respond to a referee. It engenders good will because you have made it as easy as possible for the referee to evaluate your revision.