I think keeping tolerance down has been, in effect, my life's work (I have done other things too...but it's definitely been an ongoing theme!)
I've managed pretty well too - moderation (definitely always managed that one, ahem), rotation and breaks are key (who knew??). Let's leave stimulants out of this though, because there is an entirely different narrative surrounding those..
I can still get really high on, say, 300mg nice weed smoked, 50mg of a good concentrate (dabbed), 30mg thc (eaten). Not bad after around 4 decades of use, probably averaging 5 days use per week (maybe 6, dunno - it's been more like 13 days a fortnight for last couple of years, but that one day off is crucial re tolerance, as is rotating different forms of cannabis and having some very low dose days too, sometimes just a single-skinner blunt or a small dab around 8pm)
Can also still get a nice high (and good analgesia) out of 100mg opium latex, or 20mg Morphine, 10mg Oxycodone (sometimes a noticably pleasant high off 5mg even), and that's after 17 or so years of on/off use. I know that's unusual and I've been fortunate with that - but I have followed a pretty strict dosing schedule, stuck to my boundaries and held myself accountable. Am pretty sure it would have been a different story if had started with opiates earlier in life.
Looking forward to being asked what I did with my life at the pearly gates...is it St.Peter who conducts the interrogation?
"Next please. Ah, Mr Fiend...now can you tell me your greatest achievements in life please?" ...
"Well, I did manage to keep my tolerance to some drugs down to a reasonably low level...so there's that"