There is no magical formula for "properly" standing up for yourself. People are unpredictable. How they react to your attempt to shut down their unacceptable behavior towards you can range from peaceful acceptance that they were wrong followed by an apology, to rage filled jabs in a desperate attempt to "put you in your place" for confronting them, thus leading to even worse behavior. It's a stupid game I'm tired of playing, with anyone, on any level.
If someone doesn't want to show consistent deceny and respect as I do for them, I'll just remove myself from their space since they can't reciprocate basic decency. I don't need to fight them for respect they should have just reciprocated like a decent human being. Forget that.
I try SO hard to treat people decently because I want to be treated decently. Even when I'm having a horrible day, I still manage to be neutral, because I don't want someone treating ME like crap. So, when people decide to side swipe me with horrible behavior for [insert reason], it shows me they never appreciated the neutrality and respect I've shown them, nor did they really care about consistently reciprocating basic decency. It's disappointing, it hurts. But I'm getting better at getting over it.
People need to either reciprocate the decency and respect I show them, or bother someone else with their unwillingness to do so. I'm tired of playing games with people. I'm not obligated to tolerate a person who has shown me they cannot consistently reciprocate basic decency!