Copying 天声人語/other materials

Hello everyone!

I'm really interested in improving my writing skills in Japanese, so I want to hear your opinions on what's worked best for you. In the past, I've used Anki with the cloze deletion feature to learn particle and vocabulary usage, but I found that I spent a lot of time on minor stylistic issues and didn't feel my Japanese improve that much. If you really recommend it I'd be willing to try Anki again though, but it would be helpful if you told me why Anki has been effective for you.

I was wondering if anyone here has tried copying the 天声人語 column of the 朝日新聞. If you search "天声人語 書き写し," you'll find that a lot of Japanese people seem to be doing this to improve their writing, but opinions are also mixed. From a foreigner's perspective, though, do you think it would have a greater or lesser effect? Are there any other materials that you think would be worth copying?

If anyone has other methods that really helped with writing, please let me know.
Wow, there are even special notebooks for the purpose...

(Belatedly: I have no advice to offer, but I'm interested in the replies as well... all my skills besides passive recognition need work.)
Edited: 2017-03-15, 3:41 pm
Holy crap, I never saw the notebooks - that's wild.

I'm personally trying a technique I wrote about recently where I study a writer whose style I like (recently it's the essay style of 星野源), and then trying to write out my own thoughts using some of the same sentence patterns, or changing some words to express a meaning I want to express.

I don't see a lot of value in copying 天声人語, as it's such a specific writing style, and pretty advanced to boot. I did try this with Lifehacker and some other online articles for a while, but got bored of it pretty quickly.