Based on all this experience, one thing I can say for sure is that the job search advice you get today, for whatever price, is exactly the same bullshit that the unemployed of 1971 (and 1975, and 1982...) had served up to them. Some of the items make sense. The bulk is mere witless repetition.
Leading my list of pet peeves is the amount of energy that goes into answering the question "tell me about yourself." These dozen periods of job searches work out to well over 150 actual interviews. When you toss in the interviews I've conducted over the years as a hiring manager, I've got around 200 notches in my interview shootin' iron. I made pretty much the same mistakes on my own that I did with expert advice. My own advice got me on no better, and no worse, that the experts'.
Never...not once...in all those interviews has anyone asked me that, or any variant on it; nor have I ever asked it of a candidate. There are plenty of other cliches to fall back on. When a career expert trots this one out, I take it as a sign that they have no clue what is really happening on the hiring front or, if they do, they are out of fresh ideas.
You can assess a dozen or so equally useless pieces of get-hired advice by simply grabbing the topic du jour and googling it. The value of the advice is in inverse proportion to the number of hits.
My advice? If you want it, mail me your bank account numbers, 'K? Unlike those other Robin Hoods, I've been out of work.