Just random thoughts on how deal with different people. Feel free to post your own.
In general -
In public discussions your main goal is to win the hearts of the audience, not to change the mind of your opponent or even to win the argument. Know your audience and adjust your terminology, rhetoric and argumentation accordingly. Avoid bringing up unpopular truths. Use potential trigger words such as "communism", "socialism", "capitalism", etc. sparsely. Identify common boogieman concepts and use them to your advantage even if they are ridiculous.
In private discussions you should focus on bonding rather than argumentation. Try to find common ground. Your dismissal of shitty views should be delicate. If you notice they're getting defensive don't keep pushing. Rather than making arguments against their views, make arguments in favor of yours.
Again, adapt your language to circumstances. Don't use big words when nobody else does. Do use them when your opponent does.
Suffering is the most important part of their identity. Acknowledge it. Never trivialize it. Connect it to the commodification of sex and general capitalistic alienation. Point out how great "leftist" welfare states like the Scandi countries are for NEETs. Point out how fascist society would be hell for their kind.
Most are on the deep end of identity politics, but don't realize it themselves. Use their hatred of women and feminism to antagonize liberals. Take care this doesn't happen in favor of Holla Forumsshit though.
Don't talk about your normie life. They will resent you for not suffering as they are.
If you're a girl use this to your advantage. Most are desperate to be seen by a girl, even if they don't wanna admit it.
Holla Forums -
Their racism is pathological, you can't reason them out of it. If you try to appeal to onlookers outside of their torture chamber it can be useful though, because of how retarded and uncompromising it is. Your best bet in changing the Holla Forumsyps themselves is to subtly shift the blame from le Jews to the capitalist system. Capitalism is what causes their misdirected anger in the first place. Keep in mind they're very sensitive to trigger words, so avoid them at all costs. Don't let them know you are a communist/socialist or whatever. Refer to yourself as "politically independent" or some bullshit.
Don't expect success.
Your average liberal is simply clueless. Having them get mad at all the bullshit in the world and then explain how capitalism is to blame can do a lot.
Porky sympathizers -
Just use your head to expose their lies and their bullshit. They're hopeless. You can't expect them to change but in public discussions you can make onlookers aware of their shittiness.
Kind of a creeper tactic, but I think one of THE most productive things you could do is to befriend as many ~12-16 year olds as you can and introduce leftist viewpoints to them. Most kids haven't formed any hard opinions yet and are easily malleable.
If you're comfortable with lying about your age, tell them you are a couple of years older than them. That way you gain a certain authority while remaining relatable.