I'm probably going to get downvoted, but I'm sick and tired of seeing, "Don't be a dick" thrown around.
It's a gendered insult. You wouldn't tell someone, "Don't be a "p**y," would you? Of *course not. So why is "don't be a dick" any different, especially when you could just as easily say, "Don't be an asshole"?
It's is neither helpful or specific. Sort of like telling a poor person to, "Get out of debt." Yeah, no shit? Why didn't I think of that?
It's probably he most vague piece of player "advice" out there. You start by insulting someone, warning them not to be a total weinerhead, then have to spend ten minutes explaining what being a stinky penis boo boo head entails.
Compare this charming bit of advice to stuff like: * "Bathe before the game." * "Try to give others the spotlight." * "Show up with a pizza."
...or a million other pieces of practical advice that actually get the point across in a sentence, without insulting the person you're trying to "help."