As for how to write well, here's the short version:
Write a bad version 1 as fast as you can;
rewrite it over and over;
if you can't get started, tell someone what you plan to write about, then write down what you said;
expect 80% of the ideas in an essay to happen after you start writing it;
start writing when you think of the first sentence;
write about stuff you like;
learn to recognize the approach of an ending, and when one appears, grab it.
Being a really good speaker is not merely orthogonal to having good ideas, but in many ways pushes you in the opposite direction...there's a tradeoff between smoothness and ideas. All the time you spend practicing a talk, you could instead spend making it better.
I try to write using ordinary words and simple sentences.
That kind of writing is easier to read, and the easier something is to read, the more deeply readers will engage with it. The less energy they expend on your prose, the more they'll have left for your ideas.
The stranger your tastes seem to other people, the stronger evidence they probably are of what you should do.
So I bet it would help a lot of people to ask themselves about this explicitly. What seems like work to other people that doesn't seem like work to you?
I think most people have one top idea in their mind at any given time. That's the idea their thoughts will drift toward when they're allowed to drift freely. And this idea will thus tend to get all the benefit of that type of thinking, while others are starved of it. Which means it's a disaster to let the wrong idea become the top one in your mind.
If there is such a thing as beauty, we need to be able to recognize it. We need good taste to make good things. Instead of treating beauty as an airy abstraction, to be either blathered about or avoided depending on how one feels about airy abstractions, let's try considering it as a practical question: how do you make good stuff?
If you're going to spend years working on something, you'd think it might be wise to spend at least a couple days considering different ideas, instead of going with the first that comes into your head. You'd think. But people don't. In fact, this is a constant problem when you're painting still lifes. You plonk down a bunch of stuff on a table, and maybe spend five or ten minutes rearranging it to look interesting. But you're so impatient to get started painting that ten minutes of rearranging feels very long. So you start painting. Three days later, having spent twenty hours staring at it, you're kicking yourself for having set up such an awkward and boring composition, but by then it's too late.