I shared some thoughts on this topic on a similar thread posted last year. An excerpt: 

"The key is that you need to show people using an EA mindset (thinking about consequences and counterfactuals, remembering that everyone is valuable), even if they aren't working on EA causes. Show people characters who do incredible things and invite them to contemplate the virtues of those characters, and you don't need to hammer too hard on the philosophy."

...so I suppose I'd say that (1) is important, but mostly when blended with (2). Rational fiction isn't uniquely instructive; instead, it takes lessons a reader could learn in many different ways and drives them deeper into the reader's identity than other media might be able to. There's an element of "I didn't know people could be like this" and an element of "this is the kind of person I want to be." 

I'd guess the second element is more important, since most people have heard about actual moral heroes outside of fiction, but they may not have a sense of how such people think about/experience the world.

The biggest effect of rational fiction for me was feeling the “warm” glow of the ingroup in the fiction I consumed. I could empathize with the characters. I think this kind of effect is inherently good, as feeling like you’re a minority with no culture is bad and encourages homogenization.

I was already a “rationalist” before reading rational fiction, and the fiction works have always struck me as much weaker than the content on our forums. On using them to “convert” other people to rationality … Well one of my friends really took to HPMOR, and they did have a high point of vowing “to always be a scientist,” but it didn’t have any observable effect and they didn’t even finish reading HPMOR. HPMOR is also probably the most educational of all the current stories.

Fiction, at first glance, seems like a great way to reach people who prefer art over numbers.

However on second glance, fiction thrives on the individual, on the specific, on one person's story.

We want to convey that doing 100x more good is a great outcome. But how does focusing on one perspective help us to see that the other 100 lives that we're not seeing are each just as valuable?

Is fiction even suitable for communicating EA ideas at all?

I worried that the answer to this question might be no.

However, with a bit of creativity, I think these challenges can be overcome.

Here's my approach for generating creative EA fiction ideas

• Identify the features of humanity that lead us to not do the most good. Example 1: our desire to do good is all about signalling, and optimising for signalling isn't the same as optimising for good. Example 2: our empathy is not scope-sensitive, aka the one-death-is-a-tragedy,-a-million-deaths-is-a-statistic effect.
• Imagine a world which is "tweaked" so that those features are no longer true in some way

Examples of ideas:

• Imagine a person whose empathy was scope sensitive. What would her life be like if every time she reads about the death toll in WW2, she feels 100,000,000x more empathy than at the thought of one person dying?
• Imagine if every morning when you woke up, your appearance was tweaked to make you more attractive if you had done more good and less attractive if you had done less good? And that this followed a utilitarian calculus?

These ideas are just meant to be illustrative -- I hope that others can come up with much better ideas.

One problem from a fiction-writing perspective is that such tweaks could lead to a genuine utopia. And straightforward utopias don't make for good stories.

Unfortunately authors tend to resolve this by making the utilitarian/good-maximising behaviour a subterfuge for evil. Which is sad.

I think there are other better ways of still generating a good story. These include:

• Imagine a world where just one person has this tweak and everyone else is normal. This helps us to question whether we (who don't have scope sensitive empathy, for example) are the weird ones.
• Focus on the transition. If the world suddenly changed, and everyone's desire to signal was now perfectly aligned with doing the most good, what would it mean for the mild-mannered middle-class tobacco marketeer who is suddenly signaling to the world how much harm they have done?
• Be inspired by other genres. What would a zombie novel that conveyed EA ideas look like?