Now that we know some philosophy, let's use it. Sure, mistakes are corrected by criticism, and criticism is a kind of explanation. But that's not practical knowledge. It's not enough guidance to effectively use it in your life. How do you really do it?
One of the things you'll need is humility. Don't assume you're right. Don't assume other people are wrong. Be genuinely curious what they think, and try to learn from them. Everything goes more smoothly with this kind of mindset. And it only makes sense: we're all fallible, and we all should be seeking to improve, so why not cooperate and focus on the ideas not the people? Ego doesn't help anything.
You'll need to learn to judge ideas for yourself instead of taking them on authority. If you can't understand it yourself, then it's not a very good explanation. Sure you can trust your car mechanic if you don't know anything about cars. But what you can't do is trust someone as a way of resolving a disagreement. When you take a mechanic's word for something it's because his technical advice is uncontroversial and you're not interested in the subject yourself. There's no debate going on. But whenever there is some kind of disagreement or controversy, you can't pick sides based on authority. If you don't know about it yourself, then you can't tell who is right, so just stay out of it. Or better yet, learn about it. Learning's not that hard once you get the hang of it.
Philosophical advice can sound a lot like common sense. Accept criticism? Be open minded? Don't be biased? Use good judgment? Don't be arrogant? Everyone knows that. The real issue is how to do it. So I'm going to tell you how.
But first I need to clear up one little misconception. While some good philosophy is common sense, some mistakes are common sense too. Some of the things "everyone knows" just aren't true. How can you tell the difference between a "be open minded" (which is true) and a "I think therefore I am" (which is false)? That takes philosophy. It turns out Descartes was wrong because his approach violated fallibility (not only in spirit, but also in the technical hair splitting way, so he's been decisively refuted).
Another common sense idea that's false is that we learn from experience (meaning observation using our five senses). While observation does have a role in learning, the empiricist view that makes observation primary is false. It was refuted by Karl Popper using advanced philosophy. I give this illustration to point out that really obvious ideas might not be so obvious after all. (And that's true even if Popper turns out to be mistaken. He at least showed there is more to the issue than people had realized.)