I'm fortunate in having friends & relatives in many countries, and in the last couple years they have been willing to serve as tour director/guide. I got the insider view of Barcelona & the Costa Brava, Liverpool, London, & Norway.
We don't want to see tourist spots, my Norwegian friends said, we like seeing the places you care about, that visitors wouldn't stumble upon, or appreciate if they did. (Me too.) On my end, that usually means taking people to B&H. On their end it's telling us which fishing village not to miss, where to eat non-ham tapas, & Lewis Carroll's boyhood church.
Hard to say how much of itI would have found on my own. Not very much, since I'm pretty much a "let's see what happens" sort of traveler.