The bit that I'm working on including in my life is "Some things are in our control and others not". In particular, he talks about the futility of trying to change things you can't control (how other people feel or think) and the benefits of confining your desires and actions to those things that you can change (what you do and how you react).
This doesn't mean that if I'm misunderstood I won't explain myself. It just means that it's pointless getting worked up about what goes on inside other peoples' heads.
I've seen many people depressed or angry about what other people think or feel, and it's exasperating. It doesn't matter how much you beat yourself up, rail at the injustice of it all, or call the other person a bastard. All you can control is how you react and what you do.
This is probably tied into my "say what you mean, offer clarification if questioned, but then just shut up" email practice. Sometimes I break my own rules, and normally this results in very long and ultimately futile email exchanges. I can think of very few of these that had any better outcome than if I'd just shut up after message 3.
I was turned onto Epictetus, by the way, by Dan Simmons. "Darwin's Blade" has a lot of the Epicureans, and "A Winter Haunting" has a bit more.
I'm sure there's more to the Epicureans than "pick your fights" but that's where I'm starting.