I don't come across toxicity as much, the majority of the time my team are quite pleasant.
I also keep a calm atmosphere in my games most of the time as well. Every 6 games or so, I end up muting a player and asking my teammate to mute a player if they're distracting us from our goals. A great amount of the time, we communicate quite well.
I believe when a game becomes unpleasant, is when people encourage it and not by being directly toxic. Not being a positive player gets a lot of negative players.
Such as continuously criticise your, blaming, or simply demanding your team to do something brings a lot of negative responses. You can't make anyone a target when you're trying to get your team to communicate. No pointing fingers and don't demand. Ask, be polite, try to communicate with pings and don't type as much. Because typing can be distracting, especially when you word them wrong, then players become annoyed.
These are things I do and avoid to make a game less tilting, not only for me but for my entire team.