As for 'follow the manufacturers guidelines on maintenance"
Yes, except when you shouldn't
I have two examples:
I have a Honda Mini van, it was maintained to Honda's exact requirements in the warranty period, using Honda fluids purcahsed at the dealer for the cost of an arm and a leg, all receipts and log book maintained.
The transmission on THOUSANDS of these mini vans failed. My went at 48k miles - yes 2000 miles before the Honda powertrain warranty expired (but for 10,000 miles prior to that the trans had issues, Honda was just in denial about it)
Honda gave me a new trans as I could prove maintenance - but was a HUGE fucking argument with them, but it got done
I have 160,000 on that van now, so 110.000 on the new transmission, it shifts and runs smooth as silk now
What did I change??
The Honda Z1 fluid is a fossil fluid and it SUCKS DONKEY DICKS
I switched to Valvoline Max Life Synthetic ATF when the warranty ran out. I did 4x pan drain and fills over a 2 week period (that got rid of most of the DW1 fluid) then every other oil change or in the 10,000 to 12,000 window I changed the trans fluid. I never had another problem, same with numerous people on the Ody forum
Toyota had a sludge problem on many model years of camry. I never had an issue, I changed oil every 5k with synthetic
it keeps running and running and running, no oil issues no sludge issues, no nothing, why? because I change the oil more often and use a better oil than Toyota requires
How do you know this stuff???? you don't, you get lucky sometimes that doing what your brain knows is better (I have worked on cars as a 'hobby' since I was 14 years old)