The idea that capitalism and liberal representative (I refuse to use the word democratic) government are the only viable option are so ingrained. It makes it difficult to engage anyone in serious discussion of alternatives.
What I do is point out injustice when you come across it and suggest a socialist solution. Don't mention socialism, talk about unions, worker ownership, workplace democracy, social housing, structural injustice.
If you get pushback I will say something like "I feel like our political system is so focused on capitalist solutions that often good sensible policies don't get considered"
With people you interact with frequently this approach will usually, over time, result in them no longer thinking you're a crackpot and often soften them up for a more detailed discussion in which you can discuss revolutionary change.
This is the best I have been able to do. Interested to see other responses.