As a passenger, you probably can’t tell. Cosmetic things like paint job and carpeting are redone periodically, and have nothing to do with the airworthiness of a plane. As a rule of thumb, any airliner operated by a major US, West European or first-world Asian carrier is going to be properly maintained because, in the end, it’s cheaper to keep up with maintenance than to let it slide. Outside of those, YMMV.
As for pilots, we check the logbook or equivalent to make sure everything that was written up has been addressed. Additionally we perform a “walk-around” preflight, looking for anything out of place, broken, or leaking. Sometimes we’re the ones to find things like bad spots on tires, because the last time a mechanic looked at it that spot was on the bottom and therefore undetectable. Sometimes the leak didn’t show itself until the ramp workers operated the cargo doors, and pressurized the hydraulic system. But in general, our planes are in pretty darn good shape. Modern airliners also have a phenomenal amount of redundancy, so if anything does go wonky, you won’t be in extremis.
So I wouldn’t waste my time trying to second-guess the airline, crew or maintainers. We’re doing what we’re really good at.
