It is true that the only way to get better at writing is to sit down and write. I write at least 250 words each day no matter what. I recently published a blog post on that habit, which you might find helpful as well:

http://mlafeldt.github.io/blog/write-every-day/

The post also received a lot of comments here at HN:

https://news.ycombinator.com/item?id=8350005