I made a conscious choice to write 'non work' code every day. It's now a habit (thanks largely to Github's contributions graph... I've got to get a little green square every day!). Sometimes it's just 5 minutes to refactor something or update a README, sometimes it's 5 hours to work on a project, but the result is the same - I spend more time writing code. This has introduced me to frameworks, libraries, patterns and algorithms that I wouldn't have been exposed to otherwise, and it's definitely making me a better developer.