Ask HN: What is the best way to learn copywriting?

Read letters from Gary Halbert, John Carlton and Jay Abraham. All 3 are the legends when it comes to direct response copywriting.

Other than that, you can check VSLs from Frank Kern, Chris Hadad and Ryan Deiss.

Also, check out swiped.co, you will find best ad copies/sales letter over there sorted by categories.

Go read Dan Kennedy's book titled The Ultimate Sales Letter. It's a timeless crash course on copywriting. Don't waste your time on anything else.

Try to get paid for it, you can get immediate and real feedback.