How to find a good Flying Instructor?

[Harmattan96]

What I meant is I am aware that a lot of flying instructors these days are just young blokes/girls who recently got their instructor ratings and now teaching just to get their hours up. Having said that, a lot of them don’t really have quite enough experience to teach someone to fly… Aviation is just one of those funny industries, where pilots become instructors as a first job, as opposed to last. I am a strong believer that best flying instructors are retired testing pilots, ex Capitans etc… So my question is: how do you find such flying instructors without actually offending anyone by joining a flying school and explicitly telling the young instructors that you don’t want them to teach you?

I would dissagree with that statement.
A young flight instructor, has just finished a teaching syllabus and might be just as much up to par, if not even more, compared to your crusty Captain.
A retired testing Captain or other, might not be in touch with the basic skills necessary to operate a GA aircraft, and the skill set for VFR navigation, and light aircraft aerodynamic.
Let me also emphasize that a 20 yr pilot flying intercontinental, with FMS, autopilot, and other bells and shinnies, might be much less competent as an Aviator than a systems manager.
I would say that a good flight instructor is, unfortunately, one that has probably more than a 1000hrs of dual given, living very little to the brand new guys who could be very good, but less experienced in dealing with students...and especially their mistakes.
If your old crusty Captain, is one that continously kept in touch with GA, he will be your best bet; but the one that flew airliners for eons, and decided it would be great to retire into flight training is probably more dangerous and less efficient compared to the young bushy tailed lad with an ink wet instructor certificate.
Food for thought: there is a staggering amount of ex-airline captains that kill themselves in piper arrows and other high performance single pistons, all in the name of "I have 20000hrs flying heavies, I can fly this bug smasher" attitude.