This is an update to this thread I started last month. First, there have been several thoughtful suggestions that are much appreciated. I have read the literature available from AOPA, and other places that at least acknowledge the topic. As several have pointed out. The proper use of checklists becomes even more relevant.
The initial post was a result of a gentleman I was working with who had not flown for a few years, but he still had descent stick and rudder skills, and had maintained his CFI rating. Additionally, he had attended rusty pilot training, and had prepared better than most for the flight review. He pointed out that he wanted to be be able to act as a safety pilot for some friends when they wanted to fly practice approaches during good weather.
During the flight review process, we meet several times for ground and flying. We covered appropriate ground training beyond the minimum requirements, and after the first fight together had the talk that included a respectful approach to maintaining an appropriate safety margin as some skills decline. I highlighted the necessity of investing more in preflight preparation (including orienting yourself using things like google maps to see exactly where to find airports in relation to highways, towns, structures, rivers, etc), and the need to use checklists more religiously, along with the need to write everything down (headings, altitude assignments, squawk codes, frequencies) from ATC, and to have extensive notes available on the kneeboard in the cockpit about route, fuel, altitudes, airport runways, frequencies, etc., and wisdom in having a licensed pilot to be his copilot, to help make any flight safer and more fun.
I explained what I needed to see in the flight that would determine if I could do the sign off for him. I believe the respectful and tactful discussions were actually well-received, and appreciated. He came very prepared (with the help of his son, who is also an instrument rated pilot), and earned the sign off for the flight review.
Thank you for the helpful input from your posts.