I don't launch into the spiel until asked.

When I found lemmy, I pretty much just told friends in passing "I use lemmy now, I love it" and then did not elaborate.

Instead of spreading the gospel of why federation is awesome, I just share the memes from here, and screenshots of fun threads. That way, step one is eliminating the doubt on whether there's good stuff to even be found here, and it shows that it isn't just a weird niche place for ultra-nerds.

Once they ask, I explain federation as simply as possible, glossing over most of it. I leave the subject open for further questions, but I don't info-dump on them.

Then I just pick an instance for them and help them set up an account and an app (I like thunder). From there I start sending actual links to posts and communities, which will auto-open in the app for them, getting them started with content and communities to sub to.