I'll save it for the forthcoming thread, but with the older one, it entailed a total willingness to try to understand what it's like to be a teenager in 202x, the knowledge that we cannot begin to understand what that is like, and, for a very uneasy period of time, psychiatrists, therapy, and medication. A lot of it was about finding his interest, with which a friend group follows, and the growing up process. Knowing that other friends were dealing with almost identical situations with their kids helped with parental despair. It was helpful to hear from one good friend, who said, "Do you want to feel better? Same story with all three of my kids." His kids are doing great now too.
We had to resist trying to force things. As my mom once said about me, "At a certain point, I stopped trying to raise you right and just decided to raise you."
My younger son is a different story (so far). Plays tennis, which has a built in friend group. But he has other friends that he has grown up with. Super chill. Works hard, etc. Just different people, both of whom are amazing humans.
/edit to add: Diversity never was an issue. They went to magnet schools in elementary and middle schools, both of which were "out of our district." They both always had diverse friend groups.