There’s an really interesting article at Look, Robot called “11 ways to be a better roleplayer“. The main article does have frank and profane language, so a safe-for-work version has been created too. What’s really interesting is that they all more or less embrace what for me are elements of old school play, or at least the way I’ve always played my games (and I’ve been playing for a long time).
I think #10 (“Embrace Failure”) is particularly important. This is given a lot of focus in newer games, particularly those that are tagged as “storytelling” games or games that use the idea of “fail forwarding”, but that has always been a part of playing in an old school mindset: things are NOT going going to go the way you want them to and what is important is how you react to it inside of the game and drive play on. It’s just less codified in the rule mechanics of older games and relies on player skill and interaction rather than building it into the system. In fact, #10 and #3 and #1 work together to make a cascade of action for all games (failure happens, someone tries to stop it, stuff happens next).