nice tips. Sometimes the opposite can be true though, which goes back to the whole Not a guide point. I find it very interesting when subjects are not opposites in a situation you might expect them to be.
A nugget of gold. I guess this is one of these things that you might spot if you're good or lucky, but I've never consciously looked for it. "Isolation" which you mentioned would be another good topic. One guy on the square is nearly always better than one.