You don't need to go shouting it, but if someone starts talking politics at you, fucking own it. Some coworker is like "trump sucks", say "yeah I know, I'm a communist". Your grandpa says "trump rules", say "no he sucks ass, I'm a communist". You're on a date and they ask who you're voting for? Say "I'm a communist". Cashier asks would you like change? "Yes, I am a communist".
Be open about your politics and lay claim to the title. Be a communist.
You must always choose between subtle listening and agitation and outright embracing communism.
Once you're openly a commie, closed-minded people will shut their ears, and you lose the benefit of the doubt with intentionality when listening to someone's concerns.
Choose based on the circumstances and your own rhetorical strengths.
Many people are very intrigued by the open embrace of communism. These are my favorite targets because I can be more authentic. Plus, they're usually more willing to entertain theoretical talk. I find it easier to destroy belief in an overarching, abstract system (capitalism) than a bunch of smaller issues then have to connect them.
But understand that people do talk, so don't necessarily out yourself in an environment where listening and agitation would be more suitable.