Something that was hard to learn but excellent to learn is to not be reactionary. Now what does it mean to be reactionary?
It means that you listen to what someone has to say, attempt to see where they are coming from, and if you think it is reasonable to give them a response then do it in a calm and cool manner. Do not fly off the hinges and be super passionate about something that is probably mundane and doesn't require that amount of passion.
Being reactionary is a very emotional response that tends to have very little logic in it. Pay attention to older folks in how they deal with high pressure situations or just situations in general. They are calm, collected and know how to respond appropriately. (most of the time... some old people are nuts)
Not being reactionary will help you when being talked to by supervisors, your Significant Other, strangers, potential partners, friends, etc.
Nobody likes someone freaking out on them because you don't agree with their oppinions on a TV show or movie or video game or sport or whatever it may be. Everyone has a point of view, and yes some are very very off and strange, but reacting with a high powered emotional response is only going to raise their gaurd and make them think you are unstable.
If you want a good idea of reactionary, then think of a woman dealing with PMS. Now don't go saying that they have PMS but PMS is a real thing and does effect some women to extreme lengths. It has to do with hormones changing rapidly and their brains not being able to keep up in the changes. Men can have this happen as well when taking medications. Pregnant women exhibit these things a lot because of the huge chemical changes going on the entire pregnancy and after even.
People get reactive on the internet as well and that just isn't helpful. Nobody wants to talk to someone like that. Sure, state your postion sometimes but you don't have to always be right either. Just slow your roll, cool your jets, bring down the enthusiasm of you retort, etc.