Most of us didn’t start out being leftists. Lots of us have lib or chud backgrounds but was radicalised by material circumstances and leftist propaganda.
We want more people to turn left and we cannot do anything to change the material conditions of capitalism. We can however work to improve our propaganda so it will have a broader appeal.
To get a discussion going about what is good propaganda we could use our own radicalisation stories as a starting point.
I have always been a weird nerd so for me it was listening to long lectures on YouTube that helped move me from being a succdem to believing that capitalism has to be abolished. Around the time of the financial crash in 2008 Richard Wolff’s Capitalism Hits The Fan as well as David Harvey’s lectures on Marx was hugely influential in pointing out how capitalism is foundationally incompatible with human progress. Talks by Chomsky helped me realising how thoroughly evil US imperialismnwas and Parenti’s content made me question the Cold War propaganda about the USSR and its allies that we are indoctrinated to see as common sense and get a much more nuanced view on things.
Now that I think about it, I was probably radicalized by my dad growing up. By leftist standards he is pretty much a lib, but in the southern US he is incredibly progressive. I’m way farther left than he is now, but I still love and respect him a lot. So I would say that the best thing to do is focus on the younger generations in terms of radicalization. They are easily impressionable (at least more so than adults) and if you just talk to them for a bit they seem to get the basic idea of being a leftist. Also the most important thing is to embed empathy for others into them as early as possible. That way, if you get then to care about people less fortunate than themselves, they’ll start to question the system which lets those people suffer. I hope my rambling made sense lol