Usually when you go the "I'm a fervent Stalinist" route most people will stay away, if that's what you want. Otherwise, what I tend to do is explain why that particular perspective is wrong, without mentioning specific ideologies. "Liberal democracy is flawed because you are choosing between a shit in your mouth or a piss in your ear, they are two and the same; the same shit, different smell. It's the illusion of choice, but in reality both groups represent the people behind. What we need is one party where specific members are removed, and where that party represents the people." For example, I didn't say, hell yeah, I love North Korea, but I explained the flaws.

I live in so this might not apply in countries that have more than two parties:

Most times I'm asked "Are you a Democrat or Republican?" and I answer "Neither, they both suck."

It depends on who I'm talking with.

Most of the time I will ask questions digging into why someone believes the status quo narrative, or I'll sprinkle in facts that are counter to it. I try not to get upset, and I try not to directly out myself as a communist if I'm not sure the other person also leans in that direction. If anything I make it clear that I'm anti-colonial and anti-imperial, which to a keen observer would indicate I'm in the ML sphere but to those less politically aware or more liberal it's quite meaningless.

Saying no and walking away helps a ton of its just some random stranger. It's crude, but works.

Win.

Just say the following:

"The maoist uprising against the landlords was the largest and most comprehensive proletarian revolution in history, and led to almost totally-equal redistribution of land among the peasantry."

Like another comment here touched on, if I'm not totally sure of the person's politics I'll usually just criticize the US/west from an anti-imperialist angle. It's useful because actual comrades will quickly pick up on what type of person I am (and maybe agree or make similar comments themselves) while other people will usually either politely nod or change the subject.

If it's a situation where I really don't want the people within earshot to know about my politics then I keep to uncontroversial statements. Like when the Ukraine conflict kicked off last year my coworkers were talking about it and while I wanted to say something about liquidating Nazis, I just said I felt bad for the innocents caught up in it and I hope it ends soon. Most people aren't gonna give you shit for saying "I don't want innocent people to die" lol.

I just focus on contributing questions to the discussion instead of opinions. Once someone gets started talking on politics they're usually forthcoming.

That puts you in a more informed position to decide about revealing your own stance or not.

I usually take all sides so nobody can tell my beliefs. Just go full cynic and troll them.

If you want to avoid it, just nod along or say you don't follow politics