It's interesting, I wouldn't have described Dan's writing vs Paul Graham's writing in that manner. Dan tends to be rather affect-less, with a very neutral, almost scientific tone. I agree that PG is more authoritative but there's also this contrarian, almost Pauline Kael-esque quality to his writing. Phrases like "Nerds don't care about glamour, so to them the appeal of New York is a mystery." aren't just authoritative, they're provocative and almost purposefully insulting.

I'm a little surprised that Dan wrote this otherwise very nice post on writing and didn't mention the counterbalance to writing: reading. If you want to write, read a lot. My writing owes a lot to writers such as James Baldwin, Robert Caro, Calvin Trillin, etc. Specifically, read published works. I love reading a blog post as much as anyone else but there is a marked difference in quality between a blog post and a book or a high quality newspaper article.

One could argue that reading leads to aping but I disagree that aping is necessarily bad. Experts do not always have good ideas on how to teach because they understand the deep, universal theory and therefore think that everybody should learn from the deep, universal theory. In truth, beginners can't and won't learn deep theory. You have to start with imitating your tennis instructor's serve and then move onto the underlying concept of how a serve works. Complaining that beginners don't know the underlying theory and are just imitating is essentially complaining that beginners are beginners. Plus mimicry is a good way to learn. When I fenced, I remember that some fencers would mimic famous fencers as a joke. But it really did help them find their own style by letting them play with the different styles and think outside their own conventions.

Thus my advice: read a lot of books; imitate as much as you like; and write a lot.