Some of it (and Class) is just plain good advice. Prefer nice clothes/things, but use the hell out of them and don’t be afraid to repair them. Don’t comment on how nice something someone bought is (this middle-class habit seems really weird after having it pointed out). Avoid “collectibles” and for god’s sake don’t think of them as an investment. That sort of thing.

I wore my copy out actually. That book single handily was responsible for my brief infatuated phase for wearing polos and no-sock penny-loafers while sporting a locust valley lockjaw. I'm laughing about it as I write this...

Hey now, loafers may be the best daily-wear shoe, and being socks-optional for popping over to the coffee shop or out on a quick errand is no small part of that :-)

But yeah, the book’s full of actually-decent fashion advice as long as you avoid the jokes (you can, in fact, wear polos with a button fastened) and are careful not to fall into affectation (probably avoid Nantucket reds if you’re not part of that set, for example) or it’s easy to accidentally become a walking parody. Fine line, hahaha.

TBH, I still probably naturally gravitate towards polos or button-downs, khakis, boating shoes, etc. It's really only been in the past few years (when I still traveled, sigh) that I began deliberately dressing down a bit at certain types of events, at least some of the time, because I wasn't dressed "right" for the event.