This is excellent advice. Similarly, I don't ask friends in other professions to work for me -- I ask for their advice on who to hire. If they suggest someone

This is excellent advice. Similarly, I don't ask friends in other professions to work for me -- I ask for their advice on who to hire. If they suggest someone to do the work, good, I know they'll recommend people they respect. And if they say "Oh, it'll take ten minutes -- let me show you" then I take them out to dinner. Either way our friendship continues.